Addition and Subtraction Up to 99 Class 1 Notes Maths

Introduction

Numbers help us count, but what if we want to add more or take some away? That’s where addition and subtraction come in!

• Addition helps us find the total when we put two groups together. If you have 45 marbles and get 10 more, how many do you have now?
• Subtraction helps us find what’s left when we take some away. If you have 60 balloons and 15 fly away, how many are left?

Now, let’s learn how to add and subtract numbers up to 99 in a fun and easy way!

Addition

Addition is putting numbers together to find the total. When we add, the numbers get bigger!

Let’s try with bigger numbers:

• You have 45 balloons, and your friend gives you 32 more. Now, you have 45 + 32 = 77 balloons!
• A shop has 56 pencils, and they get 21 more. Now, there are 56 + 21 = 77 pencils!
• There are 68 people on a bus, and 14 more get on. Now, there are 68 + 14 = 82 people on the bus!

Addition helps us count large numbers easily. Let’s practice and learn more fun ways to add!

Clear all your Class 1 doubts with EduRev Join for Free

Join for Free

Adding 1-digit and 2-digit Numbers up to 99

Shelly has 15 hair clips. She got 4 more. How many hair clips does Shelly have now? To know the total number of hair clips with Shelly, we add 15 and 4 using the following steps.

Let's learn how to add these numbers step-by-step.

Step 1: Add the ones.

Step 2: Add the tens.

Shelly has 19 hair clips now.

Adding 2-Digit Numbers

A florist has 32 red roses and 24 orange roses.
How many roses does he have altogether?
To know how many roses the florist has in all, we add 32 and 24 as follows in two steps.

Step 1: Add the ones.

Step 2: Add the tens.

Thus, the florist has 56 roses altogether.

Test: Addition and Subtraction Up to 99- 1

Start Test

Start Test

Subtraction

Subtraction means taking away or finding how much is left. When we subtract, the numbers get smaller.

Let’s try with bigger numbers:

• You have 75 chocolates, and you give 28 to your friends. Now, you have 75 - 28 = 47 chocolates left!
• A shop has 90 notebooks, and 35 are sold. Now, only 90 - 35 = 55 notebooks remain.
• There were 82 birds on a tree, and 19 flew away. Now, 82 - 19 = 63 birds are left.

Subtraction helps us in daily life, from counting money to sharing things. Let’s learn more fun ways to subtract!

Subtracting a 1-Digit Number from a 2-Digit Number

Let's learn with the help of an example. 

Somya had a collection of 19 hair bands. She lost 5. How many hair bands are left with her?

To find the number of hair bands left with Somya, we subtract 5 from 19 in two steps as follows.

Step 1: Subtract the ones.

Step 2: Subtract the tens.

Thus, Somya is left with 14 hair bands.

Subtracting 2-Digit Numbers

Ravi had 36 marbles. He gave 22 to his friend Anil. How many marbles are left with him?
To find how many marbles are left with Ravi, we subtract 22 from 36 in two steps as follows.

Step 1: Subtract the ones.

Step 2: Subtract the tens.

Thus, 14 marbles are left with Ravi.

Download the notes Chapter Notes: Addition and Subtraction Up to 99

Download as PDF

Download as PDF

More Ways of Addition and Subtraction

1. Addition by splitting the numbers pictorially

Add 42 and 33.

Step 1: Split the numbers into tens and ones.

Step 2: First add the ones together then add the tens together.

Step 3: Now, combine the tens and ones to get the sum.

= 7 tens + 5 ones
= 70 + 5
= 75
Thus, 42 + 33 = 75.

2. Subtraction by splitting the numbers pictorially
Subtract 32 from 43.

Step 1: Split the greater number 43 into tens and ones.

Step 2: Subtract the ones.

3 - 2 = 1

Step 3: Subtract the tens.

40 - 30 = 10

We are left with

= 1 ten + 1 one
= 10 + 1 = 11
So, 43 - 32 = 11.

3. Addition and subtraction using expanded form
Add: 23 + 46

Subtract: 69 – 23