Copyright © University of Cambridge. All rights reserved.

## 'Power Match' printed from http://nrich.maths.org/

### Why do this problem?

This
interactivity gives a really good workout in the use of powers
and logarithms. Even students who feel technically capable of
manipulating powers might turn to have relatively little intuition
as to how 'large' non-integer powers are.Various computational
tricks might emerge as students attempt to calculate irregular
powers. For example, since $2^3$ is less than 10, we know that
$2^{18}$ will be less than $10^6$.

### Possible approach

This activity can be played as a game or individually. When a
flag is incorrectly placed, can students understand why? This is
good for rooting out errors in understanding. For example,
$10^{1.5}$ is not half way between 10 and 100. Why not?

### Key questions

Do you know what the meaning of the power you are trying to
place is? Can you explain in words?

Can you relate the power in question to a simpler
approximation?

### Possible extension

Can students devise any computational tricks to help to
evaluate powers?

### Possible support

You can initially increase the range of acceptable accuracy.
Keep practising and use trial and error to hone in on the
answer.