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 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 Where are the primes? Age 11 to 16 Challenge level What can we say about all the primes which are greater than 3?
problem Three neighbours Age 7 to 14 Challenge level Take three consecutive numbers and add them together. What do you notice?
problem Network Trees Age 14 to 18 Challenge level Explore some of the different types of network, and prove a result about network trees.
problem Always Perfect Age 14 to 18 Challenge level Show that if you add 1 to the product of four consecutive numbers the answer is ALWAYS a perfect square.
problem Equivalent Pairs Age 5 to 7 Challenge level Can you match pairs of cards which show the same amount?
interactivity Interactive Balance In this simulation of a balance, you can drag numbers and parts of number sentences on to the trays. Have a play!
problem True or False? Age 7 to 11 Challenge level Without doing lots of calculations, can you decide which of these number sentences are true? How do you know?