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?

This task combines spatial awareness with addition and multiplication.

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

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?

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?

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

Mathematicians are always looking for efficient methods for solving problems. How efficient can you be?

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

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

Powers of numbers behave in surprising ways. Take a look at some of these and try to explain why they are true.

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

Use your logical-thinking skills to deduce how much Dan's crisps and ice-cream cost altogether.

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?

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

Find the product of the numbers on the routes from A to B. Which route has the smallest product? Which the largest?

Where will the point stop after it has turned through 30 000 degrees? I took out my calculator and typed 30 000 ÷ 360. How did this help?

Watch our videos of multiplication methods that you may not have met before. Can you make sense of them?

Imagine you were given the chance to win some money... and imagine you had nothing to lose...

This Sudoku puzzle can be solved with the help of small clue-numbers on the border lines between pairs of neighbouring squares of the grid.

Ahmed is making rods using different numbers of cubes. Which rod is twice the length of his first rod?

The number of plants in Mr McGregor's magic potting shed increases overnight. He'd like to put the same number of plants in each of his gardens, planting one garden each day. How can he do it?

Mr McGregor has a magic potting shed. Overnight, the number of plants in it doubles. He'd like to put the same number of plants in each of three gardens, planting one garden each day. Can he do it?

The Man is much smaller than us. Can you use the picture of him next to a mug to estimate his height and how much tea he drinks?

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

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?

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.

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

Evaluate these powers of 67. What do you notice? Can you convince someone what the answer would be to (a million sixes followed by a 7) squared?

I'm thinking of a number. My number is both a multiple of 5 and a multiple of 6. What could my number be?

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

Katie had a pack of 20 cards numbered from 1 to 20. She arranged the cards into 6 unequal piles where each pile added to the same total. What was the total and how could this be done?

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?

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?

During the third hour after midnight the hands on a clock point in the same direction (so one hand is over the top of the other). At what time, to the nearest second, does this happen?

Can you convince me of each of the following: If a square number is multiplied by a square number the product is ALWAYS a square number...

What is the largest number which, when divided into 1905, 2587, 3951, 7020 and 8725 in turn, leaves the same remainder each time?

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?

We can arrange dots in a similar way to the 5 on a dice and they usually sit quite well into a rectangular shape. How many altogether in this 3 by 5? What happens for other sizes?

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

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?

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

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

Watch this animation. What do you notice? What happens when you try more or fewer cubes in a bundle?

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

Number problems at primary level that may require resilience.

Number problems at primary level that require careful consideration.

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

Shut the Box game for an adult and child. Can you turn over the cards which match the numbers on the dice?

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