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

Can you each work out the number on your card? What do you notice? How could you sort the cards?

This article gives you a few ideas for understanding the Got It! game and how you might find a winning strategy.

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?

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.

Some Games That May Be Nice or Nasty for an adult and child. Use your knowledge of place value to beat your opponent.

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?

Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?

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.

In this 100 square, look at the green square which contains the numbers 2, 3, 12 and 13. What is the sum of the numbers that are diagonally opposite each other? What do you notice?

Number problems at primary level that may require resilience.

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?

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?

Number problems at primary level that require careful consideration.

If you have only four weights, where could you place them in order to balance this equaliser?

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

Make your own double-sided magic square. But can you complete both sides once you've made the pieces?

Place the numbers from 1 to 9 in the squares below so that the difference between joined squares is odd. How many different ways can you do this?

Choose four of the numbers from 1 to 9 to put in the squares so that the differences between joined squares are odd.

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

Move from the START to the FINISH by moving across or down to the next square. Can you find a route to make these totals?

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

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

Can you draw a continuous line through 16 numbers on this grid so that the total of the numbers you pass through is as high as possible?

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?

Investigate what happens when you add house numbers along a street in different ways.

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 arrange fifteen dominoes so that all the touching domino pieces add to 6 and the ends join up? Can you make all the joins add to 7?

Can you work out how many flowers there will be on the Amazing Splitting Plant after it has been growing for six weeks?

Sam got into an elevator. He went down five floors, up six floors, down seven floors, then got out on the second floor. On what floor did he get on?

Woof is a big dog. Yap is a little dog. Emma has 16 dog biscuits to give to the two dogs. She gave Woof 4 more biscuits than Yap. How many biscuits did each dog get?

Exactly 195 digits have been used to number the pages in a book. How many pages does the book have?

What do you notice about these squares of numbers? What is the same? What is different?

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

What happens when you add three numbers together? Will your answer be odd or even? How do you know?

Dotty Six game for an adult and child. Will you be the first to have three sixes in a straight line?

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?

In a square in which the houses are evenly spaced, numbers 3 and 10 are opposite each other. What is the smallest and what is the largest possible number of houses in the square?

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

Place this "worm" on the 100 square and find the total of the four squares it covers. Keeping its head in the same place, what other totals can you make?

Can you use the numbers on the dice to reach your end of the number line before your partner beats you?

Investigate the different distances of these car journeys and find out how long they take.

This challenge focuses on finding the sum and difference of pairs of two-digit numbers.

Find the sum and difference between a pair of two-digit numbers. Now find the sum and difference between the sum and difference! What happens?

Look carefully at the numbers. What do you notice? Can you make another square using the numbers 1 to 16, that displays the same properties?

Use five steps to count forwards or backwards in 1s or 10s to get to 50. What strategies did you use?

This challenging activity involves finding different ways to distribute fifteen items among four sets, when the sets must include three, four, five and six items.