1. Whole Numbers
Addition and Subtraction
What will we learn today?
• Subtraction of numbers up to
3 digits.

2. We have learnt this in the previous lecture.
5 0 5
tens
ones
hundreds

3. Let’s try subtraction.

4. 505 – 104 = ___
5 0 5 1 0 4
tens tens
ones ones
hundreds hundreds

5. 505 – 104 = ___
5 0 5
-
1 0 4
1
Start your workings from the right.

6. 505 – 104 = ___
5 0 5
-
1 0 4
0 1
Start your workings from the right to the left.

7. 505 – 104 = ___
5 0 5
-
1 0 4
4 0 1
The answer is 401.

8. Here’s another example.

9. 505 – 194 = ___
5 0 5
-
1 9 4
1
Start your workings from the right.

10. 505 – 194 = ___
4
5 0 5
-
1 9 4
1
When the number is too small to do subtraction,
you can ‘borrow’ from the bigger place value.

11. 505 – 194 = ___
4 +1
5 0 5
-
1 9 4
1
When the number is too small to do subtraction,
you can ‘borrow’ from the bigger place value.

12. 505 – 194 = ___
4 +1
5 0 5
-
1 9 4
1 1
10 – 9 = 1

13. 505 – 194 = ___
4 +1
5 0 5
-
1 9 4
3 1 1
4–1=3

14. Are you ready to
try out the
questions?