The number of plants in Mr McGregor's magic potting shed increases overnight. He'd like to put the same number of plants in each of his gardens, planting one garden each day. How can he do it?
What happens if you join every second point on this circle? How about every third point? Try with different steps and see if you can predict what will happen.
A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.
Can you explain the strategy for winning this game with any target?
Only one side of a two-slice toaster is working. What is the quickest way to toast both sides of three slices of bread?
Investigate the sum of the numbers on the top and bottom faces of a line of three dice. What do you notice?
Does this 'trick' for calculating multiples of 11 always work? Why or why not?
Watch this film carefully. Can you find a general rule for explaining when the dot will be this same distance from the horizontal axis?
List any 3 numbers. It is always possible to find a subset of adjacent numbers that add up to a multiple of 3. Can you explain why and prove it?
Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?
This challenge, written for the Young Mathematicians' Award, invites you to explore 'centred squares'.
How many ways can you find to do up all four buttons on my coat? How about if I had five buttons? Six ...?
In this problem we are looking at sets of parallel sticks that cross each other. What is the least number of crossings you can make? And the greatest?
Choose any 3 digits and make a 6 digit number by repeating the 3 digits in the same order (e.g. 594594). Explain why whatever digits you choose the number will always be divisible by 7, 11 and 13.
Four bags contain a large number of 1s, 3s, 5s and 7s. Pick any ten numbers from the bags above so that their total is 37.
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?
Find some examples of pairs of numbers such that their sum is a factor of their product. eg. 4 + 12 = 16 and 4 × 12 = 48 and 16 is a factor of 48.
Sweets are given out to party-goers in a particular way. Investigate the total number of sweets received by people sitting in different positions.
A three digit number abc is always divisible by 7 when 2a+3b+c is divisible by 7. Why?
This task follows on from Build it Up and takes the ideas into three dimensions!
Got It game for an adult and child. How can you play so that you know you will always win?
You can work out the number someone else is thinking of as follows. Ask a friend to think of any natural number less than 100. Then ask them to tell you the remainders when this number is divided by. . . .
This challenge focuses on finding the sum and difference of pairs of two-digit numbers.
Find the sum and difference between a pair of two-digit numbers. Now find the sum and difference between the sum and difference! What happens?
Find a route from the outside to the inside of this square, stepping on as many tiles as possible.
Can you find all the ways to get 15 at the top of this triangle of numbers? Many opportunities to work in different ways.
We can arrange dots in a similar way to the 5 on a dice and they usually sit quite well into a rectangular shape. How many altogether in this 3 by 5? What happens for other sizes?
An article for teachers and pupils that encourages you to look at the mathematical properties of similar games.
Spotting patterns can be an important first step - explaining why it is appropriate to generalise is the next step, and often the most interesting and important.
What are the areas of these triangles? What do you notice? Can you generalise to other "families" of triangles?
This challenge asks you to imagine a snake coiling on itself.
Are these statements always true, sometimes true or never true?
One block is needed to make an up-and-down staircase, with one step up and one step down. How many blocks would be needed to build an up-and-down staircase with 5 steps up and 5 steps down?
Triangular numbers can be represented by a triangular array of squares. What do you notice about the sum of identical triangle numbers?
Watch this animation. What do you notice? What happens when you try more or fewer cubes in a bundle?
Can you find sets of sloping lines that enclose a square?
Take a look at the video of this trick. Can you perform it yourself? Why is this maths and not magic?
Use the interactivity to investigate what kinds of triangles can be drawn on peg boards with different numbers of pegs.
Are these statements relating to odd and even numbers always true, sometimes true or never true?
Tom and Ben visited Numberland. Use the maps to work out the number of points each of their routes scores.
Strike it Out game for an adult and child. Can you stop your partner from being able to go?
Here are two kinds of spirals for you to explore. What do you notice?
Find out what a "fault-free" rectangle is and try to make some of your own.
An investigation that gives you the opportunity to make and justify predictions.
The aim of the game is to slide the green square from the top right hand corner to the bottom left hand corner in the least number of moves.
Watch this video to see how to roll the dice. Now it's your turn! What do you notice about the dice numbers you have recorded?
This challenge encourages you to explore dividing a three-digit number by a single-digit number.
Can you find an efficient method to work out how many handshakes there would be if hundreds of people met?
In this game for two players, the idea is to take it in turns to choose 1, 3, 5 or 7. The winner is the first to make the total 37.