Böcker av Chris Waring

A humorous guide to the hidden calculations that are essential to everything we do.

Brush up on your mental arithmetic, including percentages, averages and recurring decimals or work on your trigonometry skills, from Pythagoras' Theorem to triangle areas and angles. I Used To Know That: Maths is a fun and accessible way to re-visit all those useful tips and maths tricks that you have forgotten from your school days.