2 out of 3
This number has 903 digits. What is the sum of all 903 digits?
2 out of 3
Put a number at the top of the machine and collect a number at the bottom. What do you get? Which numbers get back to themselves?
2 out of 3
Using the numbers 1, 2, 3, 4 and 5 once and only once, and the operations x and ÷ once and only once, what is the smallest whole number you can make?
2 out of 3
All the girls would like a puzzle each for Christmas and all the boys would like a book each. Solve the riddle to find out how many puzzles and books Santa left.
2 out of 3
If the numbers 5, 7 and 4 go into this function machine, what numbers will come out?
2 out of 3
The triangles in these sets are similar - can you work out the lengths of the sides which have question marks?
2 out of 3
Using the statements, can you work out how many of each type of rabbit there are in these pens?
2 out of 3
Watch this animation. What do you notice? What happens when you try more or fewer cubes in a bundle?
2 out of 3
Your vessel, the Starship Diophantus, has become damaged in deep space. Can you use your knowledge of times tables and some lightning reflexes to survive?
2 out of 3
The Scot, John Napier, invented these strips about 400 years ago to help calculate multiplication and division. Can you work out how to use Napier's bones to find the answer to these multiplications?
