Prove that you cannot form a Magic W with a total of 12 or less or with a with a total of 18 or more.
These pictures show squares split into halves. Can you find other ways?
I'm thinking of a number. My number is both a multiple of 5 and a multiple of 6. What could my number be?
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.
Ten cards are put into five envelopes so that there are two cards in each envelope. The sum of the numbers inside it is written on each envelope. What numbers could be inside the envelopes?
Think of two whole numbers under 10, and follow the steps. I can work out both your numbers very quickly. How?
How many balls of modelling clay and how many straws does it take to make these skeleton shapes?
