BACK TO WORKSHEETS
In this activity, we will be answering mixed questions all about subtraction.
Subtracting is all about taking numbers away.
Example 1
Work out:
21 - 7
Answer
You probably know that 11 - 7 = 4, so
21 - 7 = 14
Example 2
What is the missing number?
___ - 12 = 29
Answer
Here, we use the opposite of subtraction, which is addition, to work out the starting number of the given subtraction.
We must work out 12 + 29.
Add the units 2 + 9 = 11
Add the tens 10 + 20 = 30
Add the two results 11 + 30 = 41
12 + 29 = 41
41 - 12 = 29
Example 3
Work out:
43 - 29
Answer
Here we subtract 30 instead of 29.
Then we add 1 back at the end because we subtracted 1 too many by subtracting 30 instead of 29!
43 - 30 = 13
13 + 1 = 14
43 - 29 = 14
These are just a few tips to help you to work out subtraction problems in your head. Let's try putting them into practice in the questions that follow.
