Mathematics for Class 1 (Joyful-Mathematics)

Introduction

• The information that we collect is called Data.
• Data Handling is a process of collecting organising and representing data in various form like graphe, tables, pictographs etc.                       
• Let us see an example to understand better the concept of data collecting.
• Look at the table. This table shows the number of fruits sold in a day by a fruit seller.
  

Do you know?

• Data handling represents data in the form of pictures (called pictograph). These pictographs used by various news channels to display weather report on news.

Real Life Example

• Data Handling is widely used in collection of scores of students in various exams.
• Data handling helps the doctors to keep records of their patients.
• Once we have information data, the next step is to get result from it.
• The information we get from the above data is that Mangoes are sold the most. Apples are sold the least.

Sort and organise

Look at the picture of two rooms, room A and room B.

Which room looks neat and clean?

Room B looks neat and clean as things are properly organised in Room B.
Let us understand how to sort and organise things.

• Sorting: Grouping objects on the basis of common features is called Sorting’.
• Organising: Arranging objects in a proper or systematic manner is called organising.

An organised room or display looks neat and clean. For example room B in above example.
Ramu has opened a new stationery shop. It has pens, pencils, erasers, books, notepads, envelopes, coloured chalks, papers and stickers at one place. How can he neatly arrange everything?
He can sort things and organise them on the basis of their size, shape, colour etc.
We can make a table to help us to sort our things.
Annie and her friends wants to celebrate Christmas. They want to purchase some items to decorate their Christmas tree. They prepare a list of various items, which are required to decorate the tree. The table given below shows the list of items and the number of items. This list will help Annie and her friends to remember the items to be purchased and their numbers.

Presenting Data

We can present data in the form of table, pictures, graph, bar graphs, etc. Let us understand with the help of an example. We will study graphs, bar graph in the next classes.

This is a collections of Naina’s toys.

The data for Naina’s toys can be represented as follows.

It is easier to know from data representation that there are more number of toy dogs than teddy bears and Barbie dolls.

Greater Than Sign 

• The greater than symbol in maths is placed between two values in which the first number is greater than the second number. For example 10 > 5. Here 10 is greater than 5. 
• In inequality, greater than symbol is always pointed to the greater value and the symbol consists of two equal length strokes connecting at an acute angle at the right. ( >). 

Less Than Sign

• Similarly, a less than symbol is placed between two numbers where the first number is less than the second number. An example for less than the inequality symbol is 5 < 10. It means that 5 is less than 10. 
• In inequality, less than symbol points to the smaller value where the two equal length strokes connect at an acute angle at the left (<).
• This greater than less than symbol reduces the time complexity and it makes an easy way for the reader to understand.

Equal To Sign

• The ‘equal to’ sign is used to show the equality between two numbers or values. This sign contradicts both the greater than and less than sign. Even in terms of writing the equations, we use equal to sign. It is denoted by ‘=’.
  Example: If a = 10 and b = 10, then a = b.

Summary – All the Symbols

Here, given the list of frequently used symbols in Maths explained along with the examples

Introduction

Ravi and Reena are buying ice creams at an ice cream parlour. What do they have to give in return to the ice cream vendor?

The answer is money!

• Money is used to buy things at a shop, online or in the market.
• In India, money or currency is in the form of rupees and paise.
• We use the symbol ‘₹‘ for rupee or rupees and ‘p’ for paisa or paise.

What Does Money Look Like?

• Money can look different in many ways! In India, we have shiny coins and colourful notes.
• Coins can be small and round, like the ₹1 or ₹2 coin.
• Notes, like ₹10, ₹50, or ₹100, are made of paper and have bright colours, pictures of famous people, and designs of animals or places.
• Isn’t it fun to see how each coin and note is special?

Coins

• Coins are small, shiny, and made of metal.
• They come in different sizes and shapes, like round ₹1 and ₹2 coins or even a ₹5 coin.
• Each coin has a number on it to tell us its value, like “1” for ₹1 or “10” for ₹10.
• Coins are fun to collect because some have pictures of famous people, animals, or special events.
• They’re also easy to carry in your pocket!

Notes

• Notes are colourful pieces of paper that show different amounts of money.
• They come in many sizes, like ₹10, ₹20, ₹50, and even ₹2000!
• Each note has a special design with pictures of famous people, buildings, and nature.
• You can also find big numbers on them to tell you their value.
• Unlike coins, notes are light and easy to fold, so you can keep them in your wallet or bag.

Let Us Count Money

• Counting money is like solving a fun puzzle!
• First, look at the coins and notes you have.
• Add up the values of each one.
• For example, if you have a ₹10 note and a ₹5 coin, you have ₹15 in total.
• Counting money helps you know how much you can spend or save.
• It’s an exciting way to learn math and feel like a grown-up!

Going to the Bookstore

Neerav and Nisha went to a shop to buy a book. It cost ₹ 30. They did not have an exact ₹ 30 to pay. They paid a ₹ 50 note to the shopkeeper. The shopkeeper returned ₹ 20 in the form of coins and notes of smaller values (denomination) as ₹ 10 + ₹ 5 + ₹ 5.

EduRev Tip: Notes and coins of higher denominations can be exchanged for smaller denominations.

Money Stories in Real-Life Situations

Example 1: Somya bought a pizza for ₹ 70. She also bought popcorn for ₹ 25. How much did she pay for both? Somya paid ₹ 95 for both items.
Ans:

Example 2: A chocolate costs ₹ 18 but I have only ₹ 15. How much more money do I need to buy the chocolate? I need ₹ 3 more to buy the chocolate.
Ans:

Activity

Learning Objective: Understanding and practising handling notes and coins up to rupees 20 in daily life

Preparation:

• The teacher arranges play money and some wrappers of chocolates, wafers, empty pencil boxes, etc. (The teacher can ask the students to bring real small eatable packets.)
• The teacher prepares price tags for items with the
• Sets up real shopping scenarios with the help of volunteer students.

Working:

• Divide the students into groups of four.
• Give play money to all groups. Display items with their price tags.
• Let one group enact as sellers and other group as buyers.
• Pose a situation like- I want to buy a pencil box which costs say, ₹ 19.
• Check how do they do simple addition and subtraction of money by using different combinations of coins and notes (up to rupees 20 only).
• Repeat the activity with other groups and have fun.

Multiplication as Repeated Addition

Two elephant families are going for a jungle walk.
Each family has 4 elephants.We say, there are 4 + 4 = 8 elephants going for a jungle walk.
Or
There are 2 groups of elephants and there are 4 elephants in each group.
4 + 4 = 8 is called repeated addition expression for 2 (equal sized) groups of 4 elephants each. 

Adding the same number over and over again is called repeated addition.

Tips: 4 + 4 = 8 is called repeated addition because 4 is added repeatedly.

Another Way of Writing Repeated Addition

Look at the repeated addition expression in the picture.
5 + 5 + 5 + 5 = 20Instead of adding the same number 5 over and over again 4 times, an easier way to get the answer is 4 x 5 = 20.4 x 5 = 20 is read as 4 times 5 is equal to 20. 
Or
4 multiplied by 5 is equal to 20.

Edurev Tips: ‘x’ is the sign of multiplication.
4 x 5 is the multiplication expression instead of repeated addition expression
5 + 5 + 5 + 5 = 20.

Multiplication on a Number Line

Multiplication can also be shown on a number line.
3 x 5 = 15 is represented below on the number line.
Starting from 0, there are 3 jumps and each jump covers 5 units (steps) on the number line.Or3 times 5 units covered.
Or
3 x 5 = 15 (There are 3 jumps. Each jump is of 5 units,)

Multiplication Using an Array

Let us understand another way of multiplication— by using an array. Array is an arrangement of numbers or objects in rows and columns.
Look at the picture of 15 children sitting in 3 rows and 5 columns:
Here, there are 3 equal groups of 5 children.OrThere are 3 x 5 = 15 children in all.

Number of groups x Equal number of objects in each group = Number of objects

Edurev Tips: Array tells us how many groups of equals are there.

Building Multiplication Tables or “Times Tables”

Multiplication tables can be formed by repeated addition. 

• Multiplication Table of 1
  
• Multiplication Table of 2
  
• Multiplication Table of 5
  
• Multiplication Table of 10
  

Edurev Tips:

• One multiplied by any number gives the number itself.
• In multiplication table of 5 we have either 5 or 0 in the ones place.

What is Time?

• Do you think why we wake up in the morning, go to school or play with friends during the day, and sleep at night?
• It’s all because of time! 
• Time helps us understand when to do different activities throughout the day.
• So, let’s learn more about time and the different activities we do throughout the day!

Morning

• In the morning, we wake up and get ready for the day. 
• We brush our teeth, take a bath, and have breakfast. 
• We do these activities in the morning because it’s the beginning of the day, and we need to prepare ourselves for what’s to come.
• After breakfast, we go to school or do other activities like playing with friends or helping our parents. We do these things during the daytime when the sun is up and it’s bright outside.

We wake up in the morning

Afternoon

• In the afternoon, we take a nap or have lunch. 
• We do these activities in the afternoon because it’s the time when we feel a little tired and need a break.

We have lunch in the Afternoon

Evening

• As the day goes on, we might do other activities like homework, playing sports or games, or watching TV. 
• We do these things during the evening, which is when the sun is setting, and the day is coming to an end.

We play in the Evening

Night

• Finally, at night, we get ready for bed. We brush our teeth, change into our night suits, and go to sleep. 
• We do these activities at night because it’s the end of the day, and we need to rest and recharge for the next day.

We sleep at Night

So, different activities are done at different times of the day, which helps us understand the concept of time. 

Activities take Shorter or Longer Time

• Time is something we use to know how long it takes to do different things. 
• Some things take a short time, like brushing our teeth, while other things take a long time, like eating a meal.
• When we brush our teeth, it doesn’t take us very long, maybe only a minute or two. 
• But when we eat a meal, it can take us a longer time, maybe around 20-30 minutes.
• Similarly, taking a bath or shower can take us a longer time, around 10-15 minutes, while brushing our teeth only takes us a short time.

So, time helps us understand how long it takes to do different things.

Clock

We can also use clocks and watches to keep track of time and ensure that we do all our activities on time.

• This is a clock.
• It tells us the time.
• The face of the clock is called its dial.

How many hands do we see on this clock?

We see two hands on this clock. The long hand is called the minute hand and the short hand is called the hour hand.

How many numbers do we see on this clock?
We see numbers from 1 to 12 on the face of a clock.

Activity 

​Observe the movement of the hour hand and minute hand and find which hand move faster.
Observation: The minute hand moves faster than the hour hand.

Note:

• When the minute hand points to the number 12 and the hour hand points to any number on the face ofa  clock, the time is read as 0’ clock. Example: 7 o’clock, 4 o’ clock etc.
• 1 hour = 60 minutes.

A clock has 12 numbers which stand for hours and minutes.

The long hand of the clock tells us the minutes. The shorthand of the clock tells us the hours.

Seasons

• Time keeps changing, and so does the world around us! As the months go by, we feel different kinds of weather—sometimes it’s hot, sometimes it’s cold, and sometimes it rains. 
• These changes happen because of the seasons!
• Each season brings something special.

There are four seasons:

1. Summer Season: It is hot, and the sun shines brightly. People eat ice cream and play outside.

2. Rainy Season: The rain falls, and we use umbrellas and raincoats. Frogs and flowers love the rain!

3. Winter Season: It is cold, and we wear warm clothes. Some places even have snow!

4. Spring Season: The weather is nice, and flowers bloom everywhere. Butterflies fly around.

Match the following

Match the following objects with the suitable season:

​​​​

What is a Sequence?

• A sequence is a list of things that come in a particular order.
• For example, the letters in the alphabet are in a sequence from A to Z.

Let’s look at another example. 

• Have you ever counted numbers before?
• Counting is a sequence of numbers that go in order. 
• It starts with the number one and goes up to higher numbers like two, three, four, and so on.

Extend the Sequence

Are you ready to learn about a fun concept called “sequence”? It’s all about putting things in the right order, just like when we line up for lunch or get dressed in the morning!

Example 1:  Let’s take a look at this pattern I have on the board. Do you see the arrows? The first box has an arrow pointing up, like this ↑. In the second box, the arrow is pointing towards the right, like this →. And then in the third box, it’s again pointing upwards.

Do you notice anything? That’s right – the direction of the arrow keeps changing! Up, then right, then again up. But can you guess what comes next? Let’s think about it together.

We see that the arrow in the third box is pointing upwards. So if we follow the pattern, the next arrow should point towards the right again!

Ans: The next will be arrows pointing towards our right.

Let’s play another little game to understand it better. 

Example 2: I will tell you a sequence of fruits – a mango, then an apple, and then another mango. Can you guess what comes next?

Ans: That’s right, we will follow the same sequence and place another fruit after the second mango. But what fruit should we choose? Well, let’s look at the sequence again – it goes mango, apple, mango. So after the second mango, we need to put an apple, just like before!

Now, let’s keep going. After the apple, what should we put next? You got it – another mango! So the sequence goes like this – mango, apple, mango, apple, mango, and we can keep going and going.

Patters in Shape

Let’s take a look at the shapes in this sequence and see what we can find out!

In the first box, we see a rectangle. In the second box, we see a triangle. And in the third box, we see a circle. 

What do you think will come next? 
Let’s look at the pattern so far. It goes rectangle, triangle, circle. Do you see it? It’s like a little dance of shapes, moving from one to the next!
Now, let’s look at the fourth box. What shape is there? A rectangle!
So what shape do you think will come next? That’s right, a triangle!

And what about the sixth box? There’s a circle there.
So what comes next? You got it – a rectangle!Give

Study the pattern and fill in the missing numbers

Given below is a caterpillar carrying numbers. Look, the first number on the caterpillar is 2, and the next one is 4. But then, we see a missing number! Oh no, where did it go? Don’t worry, we can solve this mystery!So by looking at the numbers we see that 2 is followed by 4, then there is a missing number which is followed by 8. So what do we get to know about this sequence? We see that 2+2 = 4, 4+2 = 6, 6+2 = 8. So we can see that the missing number is 6. That’s where the missing number went!

Now let’s keep counting with the caterpillar. We add 2 to 6, and we get 8. And then, we add 2 to 8, and we get 10! But wait, we have another missing number! So we add 2 to 10, and we get 12! And the next number on the caterpillar is 14!

But wait, there’s more missing numbers! How many are there? Three! So we add 2 to 14, and we get 16. And then, we add 2 to 16, and we get 18! And finally, we add 2 to 18, and we get 20!

When objects or shapes are placed in an order, they form a pattern. A pattern follows a rule that allows us determine to what comes next in the sequence.

What is a Pattern?

• A pattern is a repeated sequence or design that happens over and over again.
• Patterns can be found in many things around us, such as in shapes, colors, and sounds.

Let us take an example:

• Have you ever noticed the pattern in a traffic light? 
• The traffic light goes from red to green to yellow, and then back to red again. 
• This is a pattern that repeats over and over again.

Traffic Lights

Complete the Pattern

Look at the matchsticks in front of us. In the first box, we see one matchstick facing upward at an angle. In the second box, we see two matchsticks, with the second one facing downward. And in the third box, we see three matchsticks, with the third one facing upward again.Now, we need to complete the pattern for the next three empty boxes.
Ans:

Introduction

• Numbers are like magic—they help us count, measure, and play games! 
• Let’s explore the exciting world of numbers from 21 to 99 and discover how they can make everyday things even more fun. 
• Ready to start this number adventure?

Number Names (21 to 99)

Let’s start by understanding the number names for each of these two-digit numbers:

Place Value (Tens and Ones)

• In a two-digit number, the first digit represents the tens place, and the second digit represents the ones place.
• For example, in the number 56, 5 is in the tens place, and 6 is in the ones place.
• Understanding place value helps us read and write numbers correctly.

Counting (Skip Counting by Tens):

• We can count from 20 to 99 by adding 10 each time.
• For example, 20, 30, 40, 50, 60, 70, 80, 90.

Comparison of Numbers (Greater Than and Less Than)

• We can compare two two-digit numbers by looking at the digit in the tens place first.
• If the tens digits are different, the number with the greater tens digit is greater.
• If the tens digits are the same, we compare the ones digits to determine which number is greater.
• Examples: 
  45 and 63: Since 6 is greater than 4, therefore 63 is greater than 45.
  78 and 74: Since 7 is the same in both numbers, we look at the ones place. 8 is greater than 4, so 78 is greater than 74.

Let’s Count!

Numbers 21 to 30 – Let’s Count

• Numbers 21 to 30 are formed by adding the tens place (20, 30) to the units place (1 to 10).
• For example, 21 is formed by adding 20 and 1, 22 is formed by adding 20 and 2, and so on.
• Practice counting from 21 to 30 to become familiar with these numbers.

Numbers 31 to 40 – One More Ten

• Numbers 31 to 40 follow a similar pattern.
• They are formed by adding the tens place (30) to the units place (1 to 10).
• For example, 31 is formed by adding 30 and 1, 32 is formed by adding 30 and 2, and so on.
• Practice counting from 31 to 40 to get comfortable with these numbers.

Numbers 41 to 50 – Moving Forward

• Numbers 41 to 50 are created by adding the tens place (40) to the units place (1 to 10).
• For example, 41 is formed by adding 40 and 1, 42 is formed by adding 40 and 2, and so on.
• Practice counting from 41 to 50 to reinforce your understanding.

Numbers 51 to 60 – Climbing Higher

• Numbers 51 to 60 continue the pattern.
• They are formed by adding the tens place (50) to the units place (1 to 10).
• For example, 51 is formed by adding 50 and 1, 52 is formed by adding 50 and 2, and so on.
• Practice counting from 51 to 60 to become proficient with these numbers.

Numbers 61 to 70 – A New Set

• Numbers 61 to 70 are formed by adding the tens place (60) to the units place (1 to 10).
• For example, 61 is formed by adding 60 and 1, 62 is formed by adding 60 and 2, and so on.
• Practice counting from 61 to 70 to strengthen your knowledge.

Numbers 71 to 80 – Further Exploration

• Numbers 71 to 80 follow the same pattern.
• They are formed by adding the tens place (70) to the units place (1 to 10).
• For example, 71 is formed by adding 70 and 1, 72 is formed by adding 70 and 2, and so on.
• Practice counting from 71 to 80 to become more confident.

Numbers 81 to 90 – Nearing the End

• Numbers 81 to 90 are created by adding the tens place (80) to the units place (1 to 10).
• For example, 81 is formed by adding 80 and 1, 82 is formed by adding 80 and 2, and so on.
• Practice counting from 81 to 90 to solidify your understanding.

Numbers 91 to 99 – The Final Stretch

• Numbers 91 to 99 follow the same pattern as the previous sets.
• They are formed by adding the tens place (90) to the units place (1 to 9, as there is no 0 in the units place).
• For example, 91 is formed by adding 90 and 1, 92 is formed by adding 90 and 2, and so on.
• Practice counting from 91 to 99 to master these numbers.

What is the Ones and Tens Concept?

The number 10 is the first and the smallest two-digit number.

Example 1:

• Let’s take 10 pencils.

• Now make a group of 10 pencils.
• We can make only 1 group. It represents 1 Ten. But there is no single pencil remaining. It indicates 0 ones.
• So, the number 10 can write as:

Example 2:

• If we take 21 pencils, we can make 2 groups of 10 pencils that can be represented as 2 Tens.
• 1 remaining pencil can be represented as 1 Ones.
• 2 Tens and 1 Ones = 21
• We can write 21 as:

Example 3:

• We can represent 100 as 10 groups of Tens.
• We cannot write 100 as:
• We use the hundreds place. The number 100 is written as:

100 is the first and smallest three-digit number.

Let’s calculate the number of popsicles given in the table below

Missing Numbers

A series or sequence where a number is missed is known as a missing number sequence.
Look at the example given below.

What is Measurement?

• Look around! Some things are long, like a skipping rope, while others are short, like a pencil. Some objects hold a little water, like a teacup, while others hold a lot, like a big water bottle.
• We use measurement to find out how long, tall, heavy, or full something is. When we measure, we can compare—Is the table longer than the bed? Does a bucket hold more water than a mug?
• Let’s explore measurement and learn how we can compare length, distance, and capacity in fun ways!

Comparing Lengths

The teacher asks the students to stand heightwise in a line.
Akshay to Ankush: Let us stand next to each other to check who is taller, and who is shorter.

Akshay is taller than Ankush.
Ankush is shorter than Akshay.

Other students also did the same activity with each other and the line is formed as asked by the teacher.

Question: Circle the shortest shirt.

Ans:

Try yourself:Which boy is the tallest among these?

• A.(a)
• B.(b)
• C.(c)
• D.(d)

Measuring Length

Mohit and Meeta place their pencils along the edge of the tabletop to measure the length of the table.
Mohit: The length of the table is the same as 10 pencils.
Meeta: The length of the table is the same as 14 pencils.
Their measurement is different because Meeta’s pencil is shorter than Mohit’s pencil.
For correct measurement, Mohit and Meeta both should have used pencils of the same length.

Edurev Tips: If two people measure the length of the same object using the same ‘standard length’, their measurement will be the same or nearly same.

Measuring Length Using Body Parts

Long ago, people used to measure the length or height of objects using their body parts.
Some body parts that are used as units of length are shown below:

Question: What will you choose to measure the following objects?

Ans:

Comparing Mass (or Weight)

are playing on a see-saw.
is light. Ant weighs less. It has less mass.
is heavy. Elephant weighs more. It has more mass.

• In everyday routine, we consider no difference in the meaning of mass and weight. 
• Weight of an object tells how heavy or light the object is.

Question: Which candle is the lightest?

Ans:

Measuring Mass

Kripa and Vanshika are playing with their “Toy Balance” and blocks to know how heavy their toys are.
When the balance is level, it means the mass on two sides of the balance is equal.
Here, the mass of the toy car is 5 blocks.

Comparing Capacity

Capacity of a container tells how much liquid it can hold.

Question: Circle the container that can hold more water.

Ans: 

Measuring Capacity

This teapot holds 3 cups of tea. Or we can say that capacity of this teapot is 3 cupfuls.

Addition

Addition by Counting Forward

To add 6 and 3, we start from 6 and count forward by 3 as:We reach at 9. So, 6 + 3 = 9.EduRev Tips: It is easy to add if we start from the bigger number while doing addition by counting forward.

Addition on a Number Line

To add 7 and 3, we start from 7 on the number line and move 3 steps (ones) forward.We reach at 10. So, 7 + 3 = 10.

Vertical Addition

To add 6 and 2, we arrange the numbers one below the other and add as we do by forward counting as shown.Start from the bigger number 6 and count forward by 2 as:So, 6 + 2 = 8.

Properties of AdditionLet us look at the following situations to know the properties of addition.1. Adding two numbers by changing their order

While adding two numbers, the sum does not change, even if we change the order of the numbers.2. Adding 0 to a numberThere are 4 friends playing. No more friends joined them.When we add 0 to a number, the sum is the number itself.

Addition up to 20Adding 1-digit number to 10

EduRev Tips: To add 1-digit number to 10, just replace the 0 with the number. It becomes the ones place of the ‘sum’.

Addition: Counting Together by Making a Group of 10

Let us add two single digit numbers say 8 and 5 by making tens. 8 X-mas stars and 5 X-mas stars together give 13 X-mas stars.Here’s a fun way to do it:First, try to make a group of 10 stars because it’s easier to count.From the 5 stars, take 2 stars and add them to the 8 stars.Now, you have:8 stars + 2 stars = 10 stars (One group of 10!)You still have 3 stars left from the 5 stars.So, 10 stars + 3 stars = 13 stars.You have 13 Christmas stars in total.So, the sum of 8 and 5 is 13.EduRev Tips: Adding by making a group of 10 changes the question to “adding to 10”.

Addition: Counting Together by Adding Ones First

Let us add a 2-digit number and a 1-digit number say, 12 and 5.So, the sum of 12 and 5 is 17.

Addition: Counting Forward on a Number Line

Look at the given number line. It shows the numbers from 0 to 20.Let us add 11 and 6 using the number line. To find 11 + 6, start with the bigger number, 11. Now, take 6 steps (ones) forward as shown.We reach at 17. So, 11 + 6 = 17.

Adding Three Numbers

Ms Yashvi is hosting a holiday cookie party for kids. Ms Yashvi helps them in adding the number of cookies they want.

Step 1: Add any two numbers first. Get the answer.

Step 2: Now, count on to add the third number in the answer you got in step 1.Thus, Ms Yashvi got the answer 9 cookies because 3 + 2 + 4 = 9.EduRev Tips: While adding three numbers, it makes no difference which two numbers are added first.

Addition Stories in Real-Life Situations

There are 15 students in Ms Karki’s class. 3 new students join the class.How many students are there in the class now?There are 15 + 3 = 18 students in the class now.

SubtractionSubtraction by Crossing Out

There are 8 carrots in the basket. A rabbit takes away 3 carrots. How many carrots are left in the basket now?To find how many carrots are left, we cross out 3 carrots and count the remaining uncrossed carrots.There are 5 uncrossed carrots.So, 5 carrots are left in the basket.We can write it as:8 – 3 = 5 Or EduRev Tips: When we write the smaller number below the bigger number for subtraction, it is called vertical subtraction.

Subtraction by Counting Backward

To subtract 4 from 7 by backward counting, we start with the bigger number 7 and count backward 4 ones as:We reach at 3. So, 7 – 4 = 3.EduRev Tips: We count backward by ones to subtract. The number we stop at is the difference.

Properties of Subtraction

Let us look at the following situations to know the properties of subtraction.1. Subtracting 0 from a numberA monkey has 6 bananas. The monkey ate none. Now, 6 bananas are left with him.When 0 is subtracted from a number, the difference is the same number.2. Subtracting 1 from a numberA monkey has 5 bananas. The monkey ate 1 banana. Now, 4 bananas are left with him.When 1 is subtracted from a number, the difference is the number that is just before it.3. Subtracting a number from itselfA monkey has 4 bananas. The monkey ate all of them. No bananas are left with him now.When a number is subtracted from itself the difference is 0.

Subtraction Using Backward Counting on a Number Line

To subtract 4 from 10, we first start with the bigger number 10 then move 4 steps (ones) backward as shown.We reach at 6. So, 10 – 4 = 6.[Question: 777896]

Subtracting within 20Subtracting a 1-digit number from a 2-digit numberCase 1: When the ones digit is same in both the numbers.

Yajur has 15 paperclips. He lost 5 of them. How many paperclips are left with him?To find how many paperclips are left, we subtract the ones digit first. 5 ones – 5 ones = 0 ones. (As subtracting the number from itself gives 0.)Write tens digit (1) as it is.So, 15 – 5 = 10.Case 2: When the ones digit in a 2-digit number is greater than the 1-digit number.There were 16 ants in a line. 4 ants diverged from the line. How many ants are left in the line now?To find how many ants are left in the line, we subtract the ones digit first.6 ones – 4 ones = 2 ones. Write 2 below the ones column.Now, write 1 as it is in the tens place as shown.So, 16 – 4 = 12.Thus, there are 12 ants left in the line now.

Subtracting by Backward Counting

To subtract 5 from 17, we begin at 17 and count 5 ones backward.We reach 12. So, 17 – 5 = 12.

Subtraction: Backward Counting on a Number Line

Look at the number line shown below. It shows the numbers from 0 to 20.Let us subtract 6 from 14. We start with the bigger number 14 and jump back 6 steps (ones).We reach at 8. So, 14 – 6 = 8.

Subtraction Stories in Real-Life SituationsSheetal has 19 pencils. She gave 5 pencils to her brother Parag.

Parag: How many pencils are left with you now?Sheetal: 14Parag: How?Sheetal: I subtracted the pencils given to you from the total number of pencils I had as follows.So, 19 – 5 = 14.You can also count backward to subtract. Start from 19 and count back 5 ones as 19, 18, 17, 16, 15, 14.Sheetal: This is how I am left with 14 pencils.

Addition and Subtraction Relationship

For example, in the picture below there are 4 pineapples in the first set and 2 pineapples in the second set, so we say there are 6 pineapples altogether and we can write 4 + 2 = 6. If we start with 6 pineapples and take away 2, we are left with 4. We can write 6 − 2 = 4.

Problem-Solving: Simultaneous Addition and Subtraction

Let us look at the following problem:Example: A farmer had 12 mangoes. He sold 4 mangoes. Then he picked 6 more mangoes from his tree. How many mangoes does he have now?Sol: Let’s solve this step-by-step.1. The farmer had 12 mangoes.He sold 4 mangoes, so we subtract:12−4=8Now he has 8 mangoes.He then picked 6 more mangoes, so we add:8+6=14The farmer now has 14 mangoes. 

Dotty Bug and her Designs 

Page No. 33 – 34

A: Write the number of dots on each bug.

Ans:B: Make some dot designs with objects like tamarind seeds, pebbles, buttons, bindis, etc., and identify the number of dots in each arrangement.Ans: C: Identify and write the numbers formed by the arrangement of the red bindis.Ans: 

Let us Play

Page No. 34

D: Play with your friend. Roll the dice and colour a box with the same number of dots as on the dice. Take turns with your friend and roll again.

The child with more number of coloured boxes will win.Ans:

​Vanishsing Buttons

Page No. 35

Gola monkey wears his favourite shirt with four buttons. He went to the garden and ate too many bananas as he was fond of them. What do you think happened then?One of the buttons popped out and rolled away. But he cannot dream of giving up bananas and he keeps on losing all the buttons one by one.

Ans: 

Page No. 36

Write the number of birds sitting on the branch of the tree.

Ans: 

Think and Tell 

Page No. 36

A: How many suns do you see in the night?Ans: 0 Sun, I see in the night.B. How many moons do you see at noon?

Ans: 0 Moon, I see in the noon.

Tenth Birthday

Page No. 37

Ans: It is Aastha’s tenth birthday. Her father prepared halwa for her. She is celebrating the birthday with her friends.She has lighted 11 diyas on her birthday.Count and write the number of objects.Ans: 

Let us

Do Page No. 38

A: Count and draw beads to make a string of 10 beads.

Ans: B: Draw buttons to make a ten frame of buttons.Ans: 

The Handy Five and Ten 

Page No. 39

Follow the pattern and write the number pairs separated by the stick.

Ans: 

Number Pairs of 10 

Page No. 40

Ans: 

Let us TalkPage No. 19

A: Identify the birds in the picture.

Ans: B: How many animals or birds were eating the mango in the beginning?

Ans: Only 1, that is,Squirrel. C: How many more animals or birds joined every time?

Ans: One More.

D: What is 1 more than 1, 1 more than 2,… up to 9?

Ans: 1 More than 1 = 21 More than 2 = 31 More than 3 = 41 More than 4 = 51 More than 5 = 61 More than 6 = 71 More than 7 = 81 More than 8 = 9

E: How many animals and birds ate the mango at the end?

Ans: 9 animals and birds ate the mango at the end.

Match the number of birds with the number of fingers.

Page No. 20Ans: 

Match the fingers with correct number of dots (one has already been done for you).

Page No. 21

Ans: 

Let Us Play – Mine with FingersPage No. 21

Show 3 fingers to your friend. Your friend has to show 3 fingers but in a different way. Similarly, you can play for other numbers. What are the different ways of showing 4 fingers using one hand?

Ans: 5 Types

My Drawing Day Page No. 23

A drawing event held for children on ‘Ekta Diwas’ (31st October). Assign different objects to each child by drawing a line as shown in the picture.Help them to know if they have enough material.Tick ✅ more or less or equal.

Ans: 

Let us Do Page No. 24

A: Tick ✅  the one which is more in number.

Ans: B. Tick ✅  the one which is less in number.Ans: C. Tick ✅ the one which is less in number.Ans:Count and Match

Page No. 28

Ans:Count and Colour

Page No.  28

A: Colour 8 stars.Ans: B: Colour 5 flowersAns: C: Colour 6 balls.Ans: Join the Numbers in a OrderPage No. 29 – 30

A: Draw a path from numbers 1 to 9 in the correct order. The lines should not cross each other.Ans: Ans: B: A naughty monkey shuffled the number cards. Write them in a correct order from the smallest to the largest.Ans: C: The cat has walked all over the worksheet. Write down the missing numbers.Ans: Colour the Biggest Number

 Page 30 – 32Ans: A: How many yellow boxes are there?

Count and write the number.Ans: B: How many jamuns are there in the given picture? Ans: C: Write the number of sheep seen in the picture. Ans: D: Draw any Four Fruits.Ans: E: Which two groups together have 8 fruits? Encircle them.Ans: F: Which two groups together have 7 umbrellas? Encircle them.Ans: G: Which are less in number? Cups or Spoons? Encircle them.Ans: