A game that tests your understanding of remainders.

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

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

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?

Do you know a quick way to check if a number is a multiple of two? How about three, four or six?

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

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

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

What is the smallest number of answers you need to reveal in order to work out the missing headers?

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?"

The number 8888...88M9999...99 is divisible by 7 and it starts with the digit 8 repeated 50 times and ends with the digit 9 repeated 50 times. What is the value of the digit M?

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...

Imagine a wheel with different markings painted on it at regular intervals. Can you predict the colour of the 18th mark? The 100th mark?

What is the remainder when 2^2002 is divided by 7? What happens with different powers of 2?

The five digit number A679B, in base ten, is divisible by 72. What are the values of A and B?

Find a cuboid (with edges of integer values) that has a surface area of exactly 100 square units. Is there more than one? Can you find them all?

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.

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

In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?

Ben passed a third of his counters to Jack, Jack passed a quarter of his counters to Emma and Emma passed a fifth of her counters to Ben. After this they all had the same number of counters.

Find the highest power of 11 that will divide into 1000! exactly.

How many numbers less than 1000 are NOT divisible by either: a) 2 or 5; or b) 2, 5 or 7?

A game for 2 or more people. Starting with 100, subratct a number from 1 to 9 from the total. You score for making an odd number, a number ending in 0 or a multiple of 6.

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

What is the value of the digit A in the sum below: [3(230 + A)]^2 = 49280A

I'm thinking of a number. When my number is divided by 5 the remainder is 4. When my number is divided by 3 the remainder is 2. Can you find my number?

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

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

I put eggs into a basket in groups of 7 and noticed that I could easily have divided them into piles of 2, 3, 4, 5 or 6 and always have one left over. How many eggs were in the basket?

Some 4 digit numbers can be written as the product of a 3 digit number and a 2 digit number using the digits 1 to 9 each once and only once. The number 4396 can be written as just such a product. Can. . . .

A number N is divisible by 10, 90, 98 and 882 but it is NOT divisible by 50 or 270 or 686 or 1764. It is also known that N is a factor of 9261000. What is N?

Does a graph of the triangular numbers cross a graph of the six times table? If so, where? Will a graph of the square numbers cross the times table too?

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

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.

This article for teachers describes how number arrays can be a useful reprentation for many number concepts.

Using your knowledge of the properties of numbers, can you fill all the squares on the board?

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.

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?

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

How can you use just one weighing to find out which box contains the lighter ten coins out of the ten boxes?

The sum of the first 'n' natural numbers is a 3 digit number in which all the digits are the same. How many numbers have been summed?

How many integers between 1 and 1200 are NOT multiples of any of the numbers 2, 3 or 5?

A game for 2 people using a pack of cards Turn over 2 cards and try to make an odd number or a multiple of 3.

Use the interactivity to create some steady rhythms. How could you create a rhythm which sounds the same forwards as it does backwards?

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

Can you find what the last two digits of the number $4^{1999}$ are?

The number 12 = 2^2 × 3 has 6 factors. What is the smallest natural number with exactly 36 factors?

These red, yellow and blue spinners were each spun 45 times in total. Can you work out which numbers are on each spinner?

Look at three 'next door neighbours' amongst the counting numbers. Add them together. What do you notice?

Find the frequency distribution for ordinary English, and use it to help you crack the code.