Multiplication and division

problem
Calendar calculations

Age

7 to 11

Challenge level

Try adding together the dates of all the days in one week. Now multiply the first date by 7 and add 21. Can you explain what happens?
problem
Tom's number

Age

7 to 11

Challenge level

Work out Tom's number from the answers he gives his friend. He will only answer 'yes' or 'no'.
problem
Pies

Age

7 to 11

Challenge level

Grandma found her pie balanced on the scale with two weights and a quarter of a pie. So how heavy was each pie?
problem
Pumpkin pie problem

Age

7 to 11

Challenge level

Peter wanted to make two pies for a party. His mother had a recipe for him to use. However, she always made 80 pies at a time. Did Peter have enough ingredients to make two pumpkin pies?
problem
Next number

Age

7 to 11

Challenge level

Find the next number in this pattern: 3, 7, 19, 55 ...
problem
Forgot the numbers

Age

7 to 11

Challenge level

On my calculator I divided one whole number by another whole number and got the answer 3.125. If the numbers are both under 50, what are they?
problem
Make 100

Age

7 to 11

Challenge level

Find at least one way to put in some operation signs to make these digits come to 100.
problem
Practice run

Age

7 to 11

Challenge level

Chandrika was practising a long distance run. Can you work out how long the race was from the information?
problem
Please explain

Age

11 to 14

Challenge level

Visitors to Earth from the distant planet of Zub-Zorna were amazed when they found out that when the digits in this multiplication were reversed, the answer was the same! Find a way to explain why this works.
problem
Zios and Zepts

Age

7 to 11

Challenge level

On the planet Vuv there are two sorts of creatures. The Zios have 3 legs and the Zepts have 7 legs. The great planetary explorer Nico counted 52 legs. How many Zios and how many Zepts were there?