Make one big triangle so the numbers that touch on the small triangles add to 10. You could use the interactivity to help you.

Place the numbers 1 to 6 in the circles so that each number is the difference between the two numbers just below it.

As you come down the ladders of the Tall Tower you collect useful spells. Which way should you go to collect the most spells?

Can you make a cycle of pairs that add to make a square number using all the numbers in the box below, once and once only?

Is it possible to draw a 5-pointed star without taking your pencil off the paper? Is it possible to draw a 6-pointed star in the same way without taking your pen off?

Kate has eight multilink cubes. She has two red ones, two yellow, two green and two blue. She wants to fit them together to make a cube so that each colour shows on each face just once.

Use the three triangles to fill these outline shapes. Perhaps you can create some of your own shapes for a friend to fill?

Arrange the numbers 1 to 6 in each set of circles below. The sum of each side of the triangle should equal the number in its centre.

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?

Pat counts her sweets in different groups and both times she has some left over. How many sweets could she have had?

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.

Can you make dice stairs using the rules stated? How do you know you have all the possible stairs?

In this problem it is not the squares that jump, you do the jumping! The idea is to go round the track in as few jumps as possible.

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

Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.

There are three versions of this challenge. The idea is to change the colour of all the spots on the grid. Can you do it in fewer throws of the dice?

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

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.

There are three baskets, a brown one, a red one and a pink one, holding a total of 10 eggs. Can you use the information given to find out how many eggs are in each basket?

The discs for this game are kept in a flat square box with a square hole for each disc. Use the information to find out how many discs of each colour there are in the box.

Use the 'double-3 down' dominoes to make a square so that each side has eight dots.

Can you go from A to Z right through the alphabet in the hexagonal maze?

Put the numbers 1, 2, 3, 4, 5, 6 into the squares so that the numbers on each circle add up to the same amount. Can you find the rule for giving another set of six numbers?

This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?

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?

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?

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?

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

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?

A shunting puzzle for 1 person. Swop the positions of the counters at the top and bottom of the board.

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?

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

Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.

Can you make a 3x3 cube with these shapes made from small cubes?

There are 78 prisoners in a square cell block of twelve cells. The clever prison warder arranged them so there were 25 along each wall of the prison block. How did he do it?

Can you use the information to find out which cards I have used?

Your challenge is to find the longest way through the network following this rule. You can start and finish anywhere, and with any shape, as long as you follow the correct order.

Can you make the green spot travel through the tube by moving the yellow spot? Could you draw a tube that both spots would follow?

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?

What can you say about these shapes? This problem challenges you to create shapes with different areas and perimeters.

There are a number of coins on a table. One quarter of the coins show heads. If I turn over 2 coins, then one third show heads. How many coins are there altogether?

If these balls are put on a line with each ball touching the one in front and the one behind, which arrangement makes the shortest line of balls?

Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?

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

A dog is looking for a good place to bury his bone. Can you work out where he started and ended in each case? What possible routes could he have taken?

Can you find a path from a number at the top of this network to the bottom which goes through each number from 1 to 9 once and once only?

On a farm there were some hens and sheep. Altogether there were 8 heads and 22 feet. How many hens were there?

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

Strike it Out game for an adult and child. Can you stop your partner from being able to go?

Factor track is not a race but a game of skill. The idea is to go round the track in as few moves as possible, keeping to the rules.