Grade 2 Math Add two one-digit numbers

Add Two one-digit Numbers

What are one-digit numbers?

Numbers from 1 to 9 and 0 are called one-digit numbers.

Addition: Two one-digit numbers

We can add two one-digit numbers in various methods. Some methods are as follows:

1. Counting Forward Method:

Counting Forward method is the process where counting starts from a given number and the counting steps are equal to another given number. There we get the sum after finishing the counting steps.

Example:

3 + 2 = ?

Start counting from 3 and go to next 2 steps: 4, 5. We get 5 after completing the steps. And the sum is 5.

So, 3 + 2 = 5.

2. Add 0:

0 is nothing. If we add 0 to a given number, then the sum is still equal to the given number.

Example:

3 + 0 = 3.

0 + 5 = 5.

3. Make a Ten Method:

When we add two one-digit numbers and the sum is more than 9, then we can make a ten to make the sum easily.

Example:

8 + 6 = ?

Here, 8 is 2 less than 10.

So,

8 + 6

= (8+2)+(6-2)

= 10 + 4

= 14

Questions and Answers:

1. Add by 'make a ten'.

(i) 9 + 6

(ii) 6 + 5

(iii) 9 + 2

(iv) 9 + 7

(v) 7 + 5

(vi) 8 + 6

Solution:

(i) 9 + 6

à 9 + 6

= 9 + 1 + 5 [∵ 1 + 5 = 6]

= 10 + 5 [Make a ten: 9 + 1 = 10]

= 15

(ii) 6 + 5

à 6 + 5 

= 6 + 4 + 1 [∵5 = 4+1]

= 10 + 1 [Make a ten: 6 + 4 = 10]

= 11

(iii) 9 + 2

à 9 + 2

= 9 + 1 + 1 [∵ 2 = 1 + 1]

= 10 + 1 [Make a ten: 9 + 1 = 10]

= 11

(iv) 9 + 7

à 9 + 7

= 9 + 1 + 6 [∵ 7 = 1 + 6]

= 10 + 6 [Make a ten: 9 + 1 = 10]

= 16

(v) 7 + 5

à 7 + 5

= 7 + 3 + 2 [∵ 5 = 3 + 2]

= 10 + 2 [Make a ten: 7 + 3 = 10]

= 12

(vi) 8 + 6

à 8 + 6

= 8 + 2 + 4 [∵ 6 = 2 + 4]

= 10 + 4 [Make a ten: 8 + 2 = 10]

= 14

2. Add:

(i) 3 + 0 = ?

(ii) 0 + 9 = ?

(iii) 9 + 6 = ?

(iv) 9 + 9 = ?

(v) 8 + 9 = ?

Answer:

(i) 3

(ii) 9

(iii) 15

(iv) 18

(v) 17