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?
problem Mathematical Swimmer Age 11 to 14 Challenge level Can you work out how many lengths I swim each day?
problem What is Ziffle? Age 7 to 11 Challenge level Can you work out what a ziffle is on the planet Zargon?
problem What Two ...? Age 7 to 11 Challenge level 56 406 is the product of two consecutive numbers. What are these two numbers?
problem Heads and Feet Age 5 to 7 Challenge level On a farm there were some hens and sheep. Altogether there were 8 heads and 22 feet. How many hens were there?
problem Remainder Age 11 to 14 Challenge level What is the remainder when 2^2002 is divided by 7? What happens with different powers of 2?
problem Number rules - OK Age 14 to 16 Challenge level Can you produce convincing arguments that a selection of statements about numbers are true?
problem X marks the spot Age 11 to 14 Challenge level When the number x 1 x x x is multiplied by 417 this gives the answer 9 x x x 0 5 7. Find the missing digits, each of which is represented by an "x" .
problem Really Mr. Bond Age 14 to 16 Challenge level 115^2 = (110 x 120) + 25, that is 13225 895^2 = (890 x 900) + 25, that is 801025 Can you explain what is happening and generalise?
problem Divisively so Age 11 to 14 Challenge level How many numbers less than 1000 are NOT divisible by either: a) 2 or 5; or b) 2, 5 or 7?