What is the lowest number which always leaves a remainder of 1 when divided by each of the numbers from 2 to 10?

In this game, you can add, subtract, multiply or divide the numbers on the dice. Which will you do so that you get to the end of the number line first?

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.

Can you complete this calculation by filling in the missing numbers? In how many different ways can you do it?

Can you work out some different ways to balance this equation?

Can you see how these factor-multiple chains work? Find the chain which contains the smallest possible numbers. How about the largest possible numbers?

Put operations signs between the numbers 3 4 5 6 to make the highest possible number and lowest possible number.

On Friday the magic plant was only 2 centimetres tall. Every day it doubled its height. How tall was it on Monday?

Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?

Look at what happens when you take a number, square it and subtract your answer. What kind of number do you get? Can you prove it?

Use this grid to shade the numbers in the way described. Which numbers do you have left? Do you know what they are called?

Have a go at balancing this equation. Can you find different ways of doing it?

Can you complete this jigsaw of the multiplication square?

Number problems at primary level that require careful consideration.

Work out Tom's number from the answers he gives his friend. He will only answer 'yes' or 'no'.

This group activity will encourage you to share calculation strategies and to think about which strategy might be the most efficient.

Grandma found her pie balanced on the scale with two weights and a quarter of a pie. So how heavy was each pie?

Use this information to work out whether the front or back wheel of this bicycle gets more wear and tear.

Here is a chance to play a version of the classic Countdown Game.

There were 22 legs creeping across the web. How many flies? How many spiders?

Chandrika was practising a long distance run. Can you work out how long the race was from the information?

These sixteen children are standing in four lines of four, one behind the other. They are each holding a card with a number on it. Can you work out the missing numbers?

Where can you draw a line on a clock face so that the numbers on both sides have the same total?

How would you count the number of fingers in these pictures?

All the girls would like a puzzle each for Christmas and all the boys would like a book each. Solve the riddle to find out how many puzzles and books Santa left.

Use the information to work out how many gifts there are in each pile.

If the numbers 5, 7 and 4 go into this function machine, what numbers will come out?

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?

This number has 903 digits. What is the sum of all 903 digits?

Here is a picnic that Petros and Michael are going to share equally. Can you tell us what each of them will have?

Here are the prices for 1st and 2nd class mail within the UK. You have an unlimited number of each of these stamps. Which stamps would you need to post a parcel weighing 825g?

The Scot, John Napier, invented these strips about 400 years ago to help calculate multiplication and division. Can you work out how to use Napier's bones to find the answer to these multiplications?

Can you design a new shape for the twenty-eight squares and arrange the numbers in a logical way? What patterns do you notice?

Benâ€™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?

A game for 2 or more players with a pack of cards. Practise your skills of addition, subtraction, multiplication and division to hit the target score.

Amy has a box containing domino pieces but she does not think it is a complete set. She has 24 dominoes in her box and there are 125 spots on them altogether. Which of her domino pieces are missing?

This multiplication uses each of the digits 0 - 9 once and once only. Using the information given, can you replace the stars in the calculation with figures?

This big box multiplies anything that goes inside it by the same number. If you know the numbers that come out, what multiplication might be going on in the box?

Claire thinks she has the most sports cards in her album. "I have 12 pages with 2 cards on each page", says Claire. Ross counts his cards. "No! I have 3 cards on each of my pages and there are. . . .

A game for 2 people. Use your skills of addition, subtraction, multiplication and division to blast the asteroids.

There are four equal weights on one side of the scale and an apple on the other side. What can you say that is true about the apple and the weights from the picture?

Start by putting one million (1 000 000) into the display of your calculator. Can you reduce this to 7 using just the 7 key and add, subtract, multiply, divide and equals as many times as you like?

This article for teachers looks at how teachers can use problems from the NRICH site to help them teach division.

Number problems at primary level that may require determination.

There is a clock-face where the numbers have become all mixed up. Can you find out where all the numbers have got to from these ten statements?