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

This task offers an opportunity to explore all sorts of number relationships, but particularly multiplication.

Using the numbers 1, 2, 3, 4 and 5 once and only once, and the operations x and ÷ once and only once, what is the smallest whole number you can make?

In November, Liz was interviewed for an article on a parents' website about learning times tables. Read the article here.

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.

Take the number 6 469 693 230 and divide it by the first ten prime numbers and you'll find the most beautiful, most magic of all numbers. What is it?

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?

The value of the circle changes in each of the following problems. Can you discover its value in each problem?

Use the information about Sally and her brother to find out how many children there are in the Brown family.

It's Sahila's birthday and she is having a party. How could you answer these questions using a picture, with things, with numbers or symbols?

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

Number problems at primary level that may require resilience.

On a calculator, make 15 by using only the 2 key and any of the four operations keys. How many ways can you find to do it?

Annie and Ben are playing a game with a calculator. What was Annie's secret number?

Look on the back of any modern book and you will find an ISBN code. Take this code and calculate this sum in the way shown. Can you see what the answers always have in common?

After training hard, these two children have improved their results. Can you work out the length or height of their first jumps?

This task combines spatial awareness with addition and multiplication.

Resources to support understanding of multiplication and division through playing with number.

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

There are over sixty different ways of making 24 by adding, subtracting, multiplying and dividing all four numbers 4, 6, 6 and 8 (using each number only once). How many can you find?

How will you work out which numbers have been used to create this multiplication square?

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

Does this 'trick' for calculating multiples of 11 always work? Why or why not?

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?

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?

Bernard Bagnall recommends some primary school problems which use numbers from the environment around us, from clocks to house numbers.

This challenge combines addition, multiplication, perseverance and even proof.

Number problems at primary level that require careful consideration.

EWWNP means Exploring Wild and Wonderful Number Patterns Created by Yourself! Investigate what happens if we create number patterns using some simple rules.

Can you find different ways of creating paths using these paving slabs?

How would you find out how many football cards Catrina has collected?

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?

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

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?

Your vessel, the Starship Diophantus, has become damaged in deep space. Can you use your knowledge of times tables and some lightning reflexes to survive?

Put a number at the top of the machine and collect a number at the bottom. What do you get? Which numbers get back to themselves?

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

Find out what a Deca Tree is and then work out how many leaves there will be after the woodcutter has cut off a trunk, a branch, a twig and a leaf.

Skippy and Anna are locked in a room in a large castle. The key to that room, and all the other rooms, is a number. The numbers are locked away in a problem. Can you help them to get out?

The clockmaker's wife cut up his birthday cake to look like a clock face. Can you work out who received each piece?

Peter, Melanie, Amil and Jack received a total of 38 chocolate eggs. Use the information to work out how many eggs each person had.

Find another number that is one short of a square number and when you double it and add 1, the result is also a square number.

56 406 is the product of two consecutive numbers. What are these two numbers?

Annie cut this numbered cake into 3 pieces with 3 cuts so that the numbers on each piece added to the same total. Where were the cuts and what fraction of the whole cake was each piece?

There are three buckets each of which holds a maximum of 5 litres. Use the clues to work out how much liquid there is in each bucket.