Times Tables and Square Numbers (2)

Now here’s a bit of fun using square numbers and those wonderful times tables. (If you are not sure what square numbers are and how to find them, look at the Square Numbers (1) task.)

Firstly, we can try to find groups of three square numbers so that two of them add up to the third.

Here are the first few square numbers:

0    1   4   9   16   25   36 ….

Can you find two of these that add up to one of the others?

Yes, the answer is 9 + 16 = 25.

We call this group of three square numbers (9, 16 and 25) a Pythagorean Triple.

If you have not covered Pythagoras’ Theorem at school yet, you will, you will! When you do, you will find these triples quite handy, but for the moment, they are just good fun.

See how many you can find. HINT: You will need a lot more square numbers to get a good range of triples, so JUST FOR ONCE (and only this once), you can use a calculator to find them.