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

How could you arrange at least two dice in a stack so that the total of the visible spots is 18?

Put operations signs between the numbers 3 4 5 6 to make the highest possible number and lowest possible number.

What happens when you add the digits of a number then multiply the result by 2 and you keep doing this? You could try for different numbers and different rules.

Here you see the front and back views of a dodecahedron. Each vertex has been numbered so that the numbers around each pentagonal face add up to 65. Can you find all the missing numbers?

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

Max and Mandy put their number lines together to make a graph. How far had each of them moved along and up from 0 to get the counter to the place marked?

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?

Using 3 rods of integer lengths, none longer than 10 units and not using any rod more than once, you can measure all the lengths in whole units from 1 to 10 units. How many ways can you do this?

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?

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?

Explore Alex's number plumber. What questions would you like to ask? What do you think is happening to the numbers?

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

Well now, what would happen if we lost all the nines in our number system? Have a go at writing the numbers out in this way and have a look at the multiplications table.

A lady has a steel rod and a wooden pole and she knows the length of each. How can she measure out an 8 unit piece of pole?

Susie took cherries out of a bowl by following a certain pattern. How many cherries had there been in the bowl to start with if she was left with 14 single ones?

Three children are going to buy some plants for their birthdays. They will plant them within circular paths. How could they do this?

Find out why these matrices are magic. Can you work out how they were made? Can you make your own Magic Matrix?

On the planet Vuv there are two sorts of creatures. The Zios have 3 legs and the Zepts have 7 legs. The great planetary explorer Nico counted 52 legs. How many Zios and how many Zepts were there?

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

Fill in the missing numbers so that adding each pair of corner numbers gives you the number between them (in the box).

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?

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.

Arrange three 1s, three 2s and three 3s in this square so that every row, column and diagonal adds to the same total.

Vera is shopping at a market with these coins in her purse. Which things could she give exactly the right amount for?

There are nasty versions of this dice game but we'll start with the nice ones...

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

Can you score 100 by throwing rings on this board? Is there more than way to do it?

Use 4 four times with simple operations so that you get the answer 12. Can you make 15, 16 and 17 too?

Try adding together the dates of all the days in one week. Now multiply the first date by 7 and add 21. Can you explain what happens?

This group activity will encourage you to share calculation strategies and to think about which strategy might be the most efficient.

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.

How many solutions can you find to this sum? Each of the different letters stands for a different number.

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

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?

On the table there is a pile of oranges and lemons that weighs exactly one kilogram. Using the information, can you work out how many lemons there are?

Rocco ran in a 200 m race for his class. Use the information to find out how many runners there were in the race and what Rocco's finishing position was.

Fill in the numbers to make the sum of each row, column and diagonal equal to 34. For an extra challenge try the huge American Flag magic square.

Use the information to work out how many gifts there are in each pile.

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

Use these four dominoes to make a square that has the same number of dots on each side.

In this section from a calendar, put a square box around the 1st, 2nd, 8th and 9th. Add all the pairs of numbers. What do you notice about the answers?

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

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