There are lots of different methods to find out what the shapes are worth - how many can you find?
Is there a temperature at which Celsius and Fahrenheit readings are the same?
Think of a number and follow my instructions. Tell me your answer, and I'll tell you what you started with! Can you explain how I know?
A collection of short problems on equations and formulae.
In this interactivity each fruit has a hidden value. Can you deduce what each one is worth?