Can you work out how to make each side of this balance equally balanced? You can put more than one weight on a hook.
Can you find some examples when the number of Roman numerals is fewer than the number of Arabic numerals for the same number?
If you put three beads onto a tens/ones abacus you can make the numbers 3, 30, 12 or 21. What numbers can be made with six beads?
Can you create symmetrical designs by cutting a square into strips?
In this article Jenny talks about Assessing Pupils' Progress and the use of NRICH problems.
Ram divided 15 pennies among four small bags. He could then pay any sum of money from 1p to 15p without opening any bag. How many pennies did Ram put in each bag?
Try out this number trick. What happens with different starting numbers? What do you notice?
Dr James Grime takes an Enigma machine in to schools. Here he describes how the code-breaking work of Turing and his contemporaries helped to win the war.
