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.

Got It game for an adult and child. How can you play so that you know you will always win?

Can you explain the strategy for winning this game with any target?

Can you find a cuboid that has a surface area of exactly 100 square units. Is there more than one? Can you find them all?

A collection of resources to support work on Factors and Multiples at Secondary level.

Given the products of diagonally opposite cells - can you complete this Sudoku?

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.

I added together some of my neighbours' house numbers. Can you explain the patterns I noticed?

A game in which players take it in turns to choose a number. Can you block your opponent?

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.

Factors and Multiples game for an adult and child. How can you make sure you win this game?

Caroline and James pick sets of five numbers. Charlie chooses three of them that add together to make a multiple of three. Can they stop him?

You are given the Lowest Common Multiples of sets of digits. Find the digits and then solve the Sudoku.

Play this game and see if you can figure out the computer's chosen number.

Find some triples of whole numbers a, b and c such that a^2 + b^2 + c^2 is a multiple of 4. Is it necessarily the case that a, b and c must all be even? If so, can you explain why?

I added together the first 'n' positive integers and found that my answer was a 3 digit number in which all the digits were the same...

A three digit number abc is always divisible by 7 when 2a+3b+c is divisible by 7. Why?

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?

Here is a machine with four coloured lights. Can you develop a strategy to work out the rules controlling each light?

Can you find a relationship between the number of dots on the circle and the number of steps that will ensure that all points are hit?

Imagine we have four bags containing a large number of 1s, 4s, 7s and 10s. What numbers can we make?

The clues for this Sudoku are the product of the numbers in adjacent squares.

Imagine we have four bags containing numbers from a sequence. What numbers can we make now?

Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.

Helen made the conjecture that "every multiple of six has more factors than the two numbers either side of it". Is this conjecture true?

Given the products of adjacent cells, can you complete this Sudoku?

Is there an efficient way to work out how many factors a large number has?

Three people chose this as a favourite problem. It is the sort of problem that needs thinking time - but once the connection is made it gives access to many similar ideas.

Make a set of numbers that use all the digits from 1 to 9, once and once only. Add them up. The result is divisible by 9. Add each of the digits in the new number. What is their sum? Now try some. . . .

Can you find any perfect numbers? Read this article to find out more...

The items in the shopping basket add and multiply to give the same amount. What could their prices be?

Ben, Jack and Emma passed counters to each other and ended with the same number of counters. How many did they start with?

Prove that if a^2+b^2 is a multiple of 3 then both a and b are multiples of 3.

Can you find a way to identify times tables after they have been shifted up or down?

Play the divisibility game to create numbers in which the first two digits make a number divisible by 2, the first three digits make a number divisible by 3...

The puzzle can be solved by finding the values of the unknown digits (all indicated by asterisks) in the squares of the $9\times9$ grid.

An environment which simulates working with Cuisenaire rods.

Find the largest integer which divides every member of the following sequence: 1^5-1, 2^5-2, 3^5-3, ... n^5-n.

The nth term of a sequence is given by the formula n^3 + 11n . Find the first four terms of the sequence given by this formula and the first term of the sequence which is bigger than one million. . . .

Here is a Sudoku with a difference! Use information about lowest common multiples to help you solve it.

A student in a maths class was trying to get some information from her teacher. She was given some clues and then the teacher ended by saying, "Well, how old are they?"

Factor track is not a race but a game of skill. The idea is to go round the track in as few moves as possible, keeping to the rules.

Find the number which has 8 divisors, such that the product of the divisors is 331776.

Can you find any two-digit numbers that satisfy all of these statements?

Gabriel multiplied together some numbers and then erased them. Can you figure out where each number was?

Can you make lines of Cuisenaire rods that differ by 1?

Can you work out what size grid you need to read our secret message?

Follow this recipe for sieving numbers and see what interesting patterns emerge.

Data is sent in chunks of two different sizes - a yellow chunk has 5 characters and a blue chunk has 9 characters. A data slot of size 31 cannot be exactly filled with a combination of yellow and. . . .