Why does my child think 5 − (−3) = 2?
Your child treats a negative number as positive when adding or taking it away, such as working out 5 - (-3) as 2.
Why children do it
Children learn early that taking away makes a number smaller, and that rule serves them well for years. Taking away a negative breaks it: taking away a debt leaves you better off. So many children ignore the second minus sign, and treat the negative number as if it were positive.
How to help at home
Use a number line: adding a negative moves left, and taking away a negative moves right.
The right way
Calculate: 6 − (−3)
- 6 + 3Subtracting -3 is the same as adding 3.
- 9Add.
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