problem Hundred Square Age 5 to 11 Challenge level A hundred square has been printed on both sides of a piece of paper. What is on the back of 100? 58? 23? 19?
problem The Tall Tower Age 5 to 7 Challenge level As you come down the ladders of the Tall Tower you collect useful spells. Which way should you go to collect the most spells?
problem A Numbered Route Age 7 to 11 Challenge level Can you draw a continuous line through 16 numbers on this grid so that the total of the numbers you pass through is as high as possible?
problem Tilted Squares Age 11 to 14 Challenge level It's easy to work out the areas of most squares that we meet, but what if they were tilted?
problem Your number is... Age 7 to 14 Challenge level Think of a number and follow the machine's instructions... I know what your number is! Can you explain how I know?
problem Number Tracks Age 7 to 11 Challenge level Ben's class were cutting up number tracks. First they cut them into twos and added up the numbers on each piece. What patterns could they see?
problem Pair Products Age 14 to 16 Challenge level Choose four consecutive whole numbers. Multiply the first and last numbers together. Multiply the middle pair together. What do you notice?
problem Special Numbers Age 11 to 14 Challenge level My two digit number is special because adding the sum of its digits to the product of its digits gives me my original number. What could my number be?
problem Farey Sequences Age 11 to 14 Challenge level There are lots of ideas to explore in these sequences of ordered fractions.
problem Polite Numbers Age 16 to 18 Challenge level A polite number can be written as the sum of two or more consecutive positive integers, for example 8+9+10=27 is a polite number. Can you find some more polite, and impolite, numbers?