Column subtraction: 3 digit, with borrowing

Introduced in the Year 4 curriculum as: "Add and subtract numbers with up to 4 digits using the formal written methods of columnar addition and subtraction where appropriate"

When doing column subtraction, sometimes you have to borrow from the tens digit and then from the hundreds digit, too.

Press SHOW/HIDE if you need to do jottings.


Example 1:

2 is too small to subtract 9 from, so we borrow from the 5 in the 10s column.

2 becomes 12 because it borrows 1 from the 10s column. 12 subtract 9 is 3.

The 5 becomes 4 because we borrowed one from 5. 4 subtract 3 is 1.

Then we subtract the hundreds digits as normal. 4 subtract 1 is 3.


Example 2:

2 is too small to subtract 4 from, so we borrow from the 5 in the 10s column.

2 becomes 12 because it borrows 1 from the 10s column. 12 subtract 4 is 8.

The 5 becomes 4 because we borrowed one from 5.

4 is too small to subtract 6 from, so we borrow from the 7 in the 100s column.

4 becomes 14 because it borrows 1 from the 10s column. 14 subtract 6 is 8.

The 7 becomes 6 because we borrowed one from 7. 6 subtract 3 is 3.


Example 3:

4 is too small to subtract 6 from, so we try to borrow from the 10s column.

We cannot borrow from 0, so first we borrow from the 5 in the 100s column. The 5 becomes 4 because we borrowed one from 5.

The 0 becomes 10 because we have borrowed one from the 100s column.

Now, we can borrow from the 10s column. 4 in the ones column becomes 14.

14 subtract 6 is 8. The 10 becomes 9 because we borrowed from it.

9 subtract 2 is 7 and 4 subtract 3 is 1.


⯇ Browse by year group
⯇ Browse by topic area