 This is a mathematical snack from the Association of Teachers of Mathematics. Here's a number puzzle. I'm going to choose three numbers and then I'm going to do something with those numbers to get the two numbers below. And I'm going to do the same thing with those two numbers to get an answer of 11. Your first challenge is to start with your own three numbers and complete that procedure until you get a single answer at the bottom and see if you can work out how the top three numbers are connected to the answer at the bottom. When you've had a go at that you could start with four numbers and repeat the same process.