Why does my child work out only one year's interest?
Your child works out one year's interest when the question asks for several years.
Why children do it
Simple interest questions take a few steps, and children often stop after the first. One year's interest is the rate times the amount. For several years, it's that times the number of years.
How to help at home
Ask how much interest one year earns, then how many years there are.
The right way
How much simple interest is earned on $800 at 9% a year for 3 years?
- 800 × 9/100 = 72One year's interest: 9% of $800.
- 72 × 3 = 216Three years of it.
- $216The interest earned.
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