## QUOTE OF THE WEEK: “God Made the Integers. All Else is the Work of Man”

… or so thought Leopold Kronecker (1823-1891) in his famous quote. WHY KRONECKER WAS WRONG: the integers (whole numbers) include the Positive Integers or “counting numbers” 1, 2, 3, 4 and so on: easy for a child to understand. We could quite reasonably argue they are “made by God”. But the integers also include zero,

## HYPOTHESIS TESTS

In statistics, these wonderful techniques allow us to use some data that we have collected to make predictions and conclusions about the real world. AN EXAMPLE: Amy and Bill are playing snakes and ladders, but Amy thinks Bill is cheating because he keeps rolling a six. Bill insists he is just being lucky. They decide

## FACTORIALS!

Factorials are so cool that the notation is: AN EXCLAMATION MARK!!!! The exclamation mark means something very specific in maths. It’s great to be impressed with numbers, but please do not put an exclamation mark after a number just to show that it’s really cool. WHAT IS IT? n Factorial (written $n!$) means the product

## WORD OF THE WEEK: INDEX

INDEX (plural indices): you can see these in expressions like $5^2 = 25$. The 5 is called the BASE, the 2 is called the EXPONENT or INDEX, and the 25 is called a power (in this case it’s a power of 5).

## GEOMETRY PUZZLE: WHAT SHAPE DO YOU SEE?

TRICKY TILINGS:
Tiling stores are like treasure troves of geometrical amusement. Here’s a photo I took yesterday. The puzzle is simply: what shape(s) do you see?