Place value

problem
Less is more

Age

7 to 11

Challenge level

Use your knowledge of place value to try to win this game. How will you maximise your score?
problem
An easy way to multiply by 10?

Age

7 to 11

Challenge level

Do you agree with Badger's statements? Is Badger's reasoning 'watertight'? Why or why not?
game

Calculator bingo

Age

7 to 11

Challenge level

This is a game for two players. What must you subtract to remove the rolled digit from your number? The first to zero wins!
problem
Six is the sum

Age

7 to 11

Challenge level

What do the digits in the number fifteen add up to? How many other numbers have digits with the same total but no zeros?
problem
All the digits

Age

7 to 11

Challenge level

This multiplication uses each of the digits 0 - 9 once and once only. Using the information given, can you replace the stars in the calculation with figures?
problem
Reach 100

Age

7 to 11

Challenge level

Choose four different digits from 1-9 and put one in each box so that the resulting four two-digit numbers add to a total of 100.
problem
Oddly

Age

7 to 11

Challenge level

Find the sum of all three-digit numbers each of whose digits is odd.
problem
One million to seven

Age

7 to 11

Challenge level

Start by putting one million (1 000 000) into the display of your calculator. Can you reduce this to 7 using just the 7 key and add, subtract, multiply, divide and equals as many times as you like?
problem
Song book

Age

7 to 11

Challenge level

A school song book contains 700 songs. The numbers of the songs are displayed by combining special small single-digit cards. What is the minimum number of small cards that is needed?
problem
Subtraction surprise

Age

7 to 14

Challenge level

Try out these calculations. Are you surprised by the results?