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?

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

Are you resilient enough to solve these number problems?

In this article for teachers, Elizabeth Carruthers and Maulfry Worthington explore the differences between 'recording mathematics' and 'representing mathematical thinking'.

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?

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

This problem is based on a code using two different prime numbers less than 10. You'll need to multiply them together and shift the alphabet forwards by the result. Can you decipher the code?

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

On my calculator I divided one whole number by another whole number and got the answer 3.125. If the numbers are both under 50, what are they?

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

How many starfish could there be on the beach, and how many children, if I can see 28 arms?

Can you arrange 5 different digits (from 0 - 9) in the cross in the way described?

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

Twizzle, a female giraffe, needs transporting to another zoo. Which route will give the fastest journey?

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?

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?

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?

Using the statements, can you work out how many of each type of rabbit there are in these pens?

Number problems at primary level that may require resilience.

Amy has a box containing domino pieces but she does not think it is a complete set. Which of her domino pieces are missing?

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

This article for primary teachers encourages exploration of two fundamental ideas, exchange and 'unitising', which will help children become more fluent when calculating.

Four Go game for an adult and child. Will you be the first to have four numbers in a row on the number line?

This magic square has operations written in it, to make it into a maze. Start wherever you like, go through every cell and go out a total of 15!

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

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

Cherri, Saxon, Mel and Paul are friends. They are all different ages. Can you find out the age of each friend using the information?

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?

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.

There are 44 people coming to a dinner party. There are 15 square tables that seat 4 people. Find a way to seat the 44 people using all 15 tables, with no empty places.

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

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.

Use your logical reasoning to work out how many cows and how many sheep there are in each field.

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.

Number problems at primary level that require careful consideration.

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

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

There were chews for 2p, mini eggs for 3p, Chocko bars for 5p and lollypops for 7p in the sweet shop. What could each of the children buy with their money?

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.

In this investigation, you are challenged to make mobile phone numbers which are easy to remember. What happens if you make a sequence adding 2 each time?

What do you notice about the date 03.06.09? Or 08.01.09? This challenge invites you to investigate some interesting dates yourself.

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

Go through the maze, collecting and losing your money as you go. Which route gives you the highest return? And the lowest?

A group of children are using measuring cylinders but they lose the labels. Can you help relabel them?

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

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

Find the next number in this pattern: 3, 7, 19, 55 ...