game
Favourite
Dicey operations in line
Who said that adding, subtracting, multiplying and dividing couldn't be fun?
Place value
problem
Favourite
Subtraction surprise
Age
7 to 14
Challenge level
Try out some calculations. Are you surprised by the results?
problem
Skeleton
Age
11 to 14
Challenge level
Amazing as it may seem the three fives remaining in the following `skeleton' are sufficient to reconstruct the entire long division sum.
problem
Napier's bones
Age
7 to 11
Challenge level
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?
problem
Football sum
Age
11 to 14
Challenge level
Find the values of the nine letters in the sum: FOOT + BALL = GAME
game
Dicey operations in line for two
Dicey Operations for an adult and child. Can you get close to 1000 than your partner?
game
Nice or nasty for two
Some Games That May Be Nice or Nasty for an adult and child. Use your knowledge of place value to beat your opponent.
problem
Novemberish
Age
14 to 16
Challenge level
a) A four digit number (in base 10) aabb is a perfect square. Discuss ways of systematically finding this number.
(b) Prove that 11^{10}-1 is divisible by 100.
problem
Never prime
Age
14 to 16
Challenge level
If a two digit number has its digits reversed and the smaller of the two numbers is subtracted from the larger, prove the difference can never be prime.
problem
Read this page
Age
11 to 14
Challenge level
Replace the letters with numbers to make the addition work out
correctly. R E A D + T H I S = P A G E