
problem
Hidden rectangles
Rectangles are considered different if they vary in size or have different locations. How many different rectangles can be drawn on a chessboard?
Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?
A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.
The Egyptians expressed all fractions as the sum of different unit fractions. Here is a chance to explore how they could have written different fractions.
We start with one yellow cube and build around it to make a 3x3x3 cube with red cubes. Then we build around that red cube with blue cubes and so on. How many cubes of each colour have we used?
Can you make square numbers by adding two prime numbers together?