Multiplication and division

problem

Sept03 Sept03 Sept03

Age

7 to 11

Challenge level

This number has 903 digits. What is the sum of all 903 digits?
problem

The Number Crunching Machine

Age

7 to 11

Challenge level

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?
problem

1, 2, 3, 4, 5

Age

7 to 11

Challenge level

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?
problem

Clever Santa

Age

7 to 11

Challenge level

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.
problem

The Pied Piper of Hamelin

Age

7 to 11

Challenge level

This problem is based on the story of the Pied Piper of Hamelin. Investigate the different numbers of people and rats there could have been if you know how many legs there are altogether!
problem

Function Machines

Age

7 to 11

Challenge level

If the numbers 5, 7 and 4 go into this function machine, what numbers will come out?
problem

Number the Sides

Age

7 to 11

Challenge level

The triangles in these sets are similar - can you work out the lengths of the sides which have question marks?
problem

Rabbits in the Pen

Age

7 to 11

Challenge level

Using the statements, can you work out how many of each type of rabbit there are in these pens?
problem

Bundles of Cubes

Age

7 to 11

Challenge level

Watch this animation. What do you notice? What happens when you try more or fewer cubes in a bundle?
game

Ducking and Dividing

Age

7 to 11

Challenge level

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?