Multiplication and division

problem
Producing zeros

Age

11 to 14

Challenge level

Weekly Problem 10 - 2008
If the numbers 1 to 10 are all multiplied together, how many zeros are at the end of the answer?
problem
Shape times shape

Age

7 to 11

Challenge level

These eleven shapes each stand for a different number. Can you use the number sentences to work out what they are?
problem
Alphabetti Sudoku

Age

11 to 16

Challenge level

This Sudoku requires you to do some working backwards before working forwards.
problem
Secret number

Age

5 to 7

Challenge level

Annie and Ben are playing a game with a calculator. What was Annie's secret number?
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
Four go

Age

7 to 11

Challenge level

This challenge is a game for two players. Choose two of the numbers to multiply or divide, then mark your answer on the number line. Can you get four in a row?
problem
Route product

Age

7 to 11

Challenge level

Find the product of the numbers on the routes from A to B. Which route has the smallest product? Which the largest?
problem
Round and round and round

Age

11 to 14

Challenge level

Where will the point stop after it has turned through 30 000 degrees? I took out my calculator and typed 30 000 ÷ 360. How did this help?
problem
Integrated product Sudoku

Age

11 to 16

Challenge level

This Sudoku puzzle can be solved with the help of small clue-numbers on the border lines between pairs of neighbouring squares of the grid.
problem
Making longer, making shorter

Age

5 to 7

Challenge level

Ahmed is making rods using different numbers of cubes. Which rod is twice the length of his first rod?