Why does my child think $80 reduced by 15% is $65?
Your child takes away or adds the percentage as a number, such as $80 reduced by 15% = $65.
Why children do it
The 15 in 15% looks like a number to take away, so children take away $15. But the discount is 15% of the price, which is $12, so the new price is $68. Working out the discount first avoids it.
How to help at home
Ask them to work out what 15% of the price is first, before taking anything away.
The right way
A $160 jacket is reduced by 10%. What is the new price?
- 160 × 10/100 = 16Find 10% of $160: that's how much it goes down.
- 160 − 16 = 144Subtract it, because the price goes down.
- $144The new price.
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