Why does my child think 8^(1/3) = 8/3?
Your child divides by the bottom of a fractional index, such as 8^(1/3) as 8 ÷ 3 instead of 2.
Why children do it
Children read the fraction as a division, which it is everywhere else. But as a power it means a root: 8^(1/3) is the number that, multiplied by itself 3 times, makes 8, so it's 2. And 8^(2/3) is that root squared: 4.
How to help at home
Ask them which number times itself 3 times makes 8: that's 8^(1/3).
The right way
Work out: 8^(1/3)
- 2 × 2 × 2 = 82 multiplied by itself 3 times makes 8.
- 2So the cube root of 8 is 2.
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