Adding and taking away within 18 · Usually met around P1
Subtracting within 10
Ask: what adds on to get there?
How to do it
Method
Ask: what adds on to get there?
10 − 7: 7 + 3 = 10, so it's 3
Another way
Number bonds
10 splits into 7 and 3, so 10 − 7 = 3
In full
Don't count backwards. Ask yourself, 'What do I add to get there?' 10 − 7 means 'seven plus what makes ten?', and that's 3. Subtraction is just addition asked backwards.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
6 − 3
Show the answer and working
Answer: 6 − 3 = 3
Ask "3 plus what makes 6?", 3 + 3 = 6, so it's 3
Example 2
8 − 5
Show the answer and working
Answer: 8 − 5 = 3
Ask "5 plus what makes 8?", 5 + 3 = 8, so it's 3
Example 3
8 − 6
Show the answer and working
Answer: 8 − 6 = 2
Ask "6 plus what makes 8?", 6 + 2 = 8, so it's 2
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