problem
Strike it out
Age
5 to 11
Challenge level
Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.
problem
Three consecutive odd numbers
Age
11 to 16
Challenge level
How many sets of three consecutive odd numbers can you find, in which all three numbers are prime?
problem
Adding odd numbers
Age
11 to 16
Challenge level
Is there a quick and easy way to calculate the sum of the first 100 odd numbers?
problem
What does it all add up to?
Age
11 to 18
Challenge level
If you take four consecutive numbers and add them together, the answer will always be even. What else do you notice?
problem
Pythagoras proofs
Age
11 to 16
Challenge level
Can you make sense of these three proofs of Pythagoras' Theorem?
problem
Different products
Age
14 to 16
Challenge level
Take four consecutive whole numbers. Multiply the first and last numbers together. Multiply the middle pair together. What do you notice?
problem
Kite in a square
Age
14 to 18
Challenge level
Can you make sense of the three methods to work out what fraction of the total area is shaded?
interactivity
Proof sorter - quadratic equation
Age
14 to 18
Challenge level
This is an interactivity in which you have to sort the steps in the
completion of the square into the correct order to prove the
formula for the solutions of quadratic equations.
problem
Iff
Age
14 to 18
Challenge level
Take a triangular number, multiply it by 8 and add 1. What is special about your answer? Can you prove it?
problem
Curve fitter
Age
14 to 18
Challenge level
This problem challenges you to find cubic equations which satisfy different conditions.
interactivity
Proof sorter - geometric sequence
Age
16 to 18
Challenge level
Can you correctly order the steps in the proof of the formula for the sum of the first n terms in a geometric sequence?
interactivity
Proof sorter - the square root of 2 is irrational
Age
16 to 18
Challenge level
Try this interactivity to familiarise yourself with the proof that the square root of 2 is irrational. Sort the steps of the proof into the correct order.
interactivity
Proof sorter - sum of an arithmetic sequence
Age
16 to 18
Challenge level
Put the steps of this proof in order to find the formula for the sum of an arithmetic sequence