CLASS-2
DOUBLE DIGIT SUBTRACTION WITH REGROUPING

METHOD 

Step 1. – Subtract the ‘Ones’

But, 5 ‘Ones’ < 7 ‘Ones’

There are not enough ‘Ones’, so, Re-group. 

3  Tens and 5 Ones. So, place/add 1 before 5 ‘Ones’ , now the number stands 15 and then subtract  7 from 15. 

15 ‘Ones’ – 7 ‘Ones’ = 8 ‘Ones.

Write 8 in the ‘Ones’ column.

Step 2. – In Step 1. We have placed/added 1 before 5. 

‘Ones’ and Now, to balance subtract 1 from 3 ‘Tens’ and then the number stands at 2 ‘Tens’. Now, subtract 1 ‘Ten’ from 2 ‘Tens’.

2 ‘Tens’ – 1 ‘Ten’ = 1 ‘Ten’.

Write ‘1’ in the ‘Tens’ column.

So, the answer is 18       (Ans.)

Q. 2) Subtract 47 - 39 = ?

METHOD

Step 1.– Subtract the ‘Ones’

But, 7 ‘Ones’ < 9 ‘Ones’

There are not enough ‘Ones’, so, Re-group. 

4  Tens and 7 Ones. So, place/add 1 

before 7 ‘Ones’, now the number

stands 17 and then subtract  9 from 17. 

 17 ‘Ones’ – 9 ‘Ones’ = 8 ‘Ones’

 Write 8 in the ‘Ones’ column.

Step 2.– In Step 1. We have placed/added 1 before 7 ‘Ones’ and Now, to balance subtract 1 from 4 ‘Tens’ and then the number stands at 3 ‘Tens’. Now, subtract 3 ‘Ten’ from 3 ‘Tens’.

3 ‘Tens’ – 3 ‘Ten’ = 0 ‘Ten’.

Write ‘0’ in the ‘Tens’ column.

 So, the answer is 8         (Ans.)

(As you Know value of ZERO before number is none/nothing/no-value)  

Q. 3) Subtract 72 - 28 = ?

METHOD

Step 1.– Subtract the ‘Ones’

But, 2 ‘Ones’ <  4 ‘Ones’

There are not enough ‘Ones’, so, Re-group.

7  Tens and 2 Ones. So, place/add 1

before 2 ‘Ones’, now the number

stands 12 and then subtract 8 from 12. 

  12 ‘Ones’ – 8 ‘Ones’ = 4 ‘Ones’

  Write 4 in the ‘Ones’ column.

Step 2.– In Step 1. We have placed/added 1 before 7 ‘Ones’ and Now, to balance subtract 1 from 7 ‘Tens’ and then the number stands at 6 ‘Tens’. Now, subtract 

2 ‘Tens’ from 6 ‘Tens’.

 6 ‘Tens’ – 2 ‘Ten’ = 4 ‘Ten’.

 Write ‘4’ in the ‘Tens’ column.

 So, the answer is 44        (Ans.)