Advanced search

Maths tricks

(3 Posts)
joanbyers Sun 18-Nov-12 18:07:26

DS (who is 10) was moaning in the toy shop earlier because we were looking at toys for his sister, and so to keep him quiet I asked him 26x26, 28x28, etc., which didn't take him long, so gave him 112x112, which he said was 14 squared times 8 squared (which is true), and came up with the answer I think based on 14^2 [196] x 8 x 2 x 2 x 2.

Anyway are there any tricks to do harder mental arithmetic that I could perhaps teach him?

numbum Sun 18-Nov-12 20:08:38

I've got an app on my phone that DS enjoys called 'Epic Maths Tricks'. I can't comment on it myself because he's better at maths than me so I don't get what he's doing half of the time and have to check his answers with a calculator

sashh Mon 19-Nov-12 05:27:30

Does he know about adding indeces?

so 8^2 *8^2 = 8^4

He obviosly sees patterns and squared is no problem so how about square rooting and iterration.

So you know the sq root of 9 = 3 and the square root of 16 =4 so what is the square root of 12?

he has to make a guess, which will be between 3 and 4 (12 is between 9 and 16, so the squareroot will be between the square roots).

Make a gues, square it and looking at the result should your next guess be higher or lower?

If he has access to programming software he can write a small program that will do it for him. And explain how his calculator works.

Join the discussion

Registering is free, easy, and means you can join in the discussion, watch threads, get discounts, win prizes and lots more.

Register now »

Already registered? Log in with: