If you have ten counters numbered 1 to 10, how many can you put into pairs that add to 10? Which ones do you have to leave out? Why?

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

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

Use the number weights to find different ways of balancing the equaliser.

In how many ways could Mrs Beeswax put ten coins into her three puddings so that each pudding ended up with at least two coins?

Imagine a pyramid which is built in square layers of small cubes. If we number the cubes from the top, starting with 1, can you picture which cubes are directly below this first cube?

In Sam and Jill's garden there are two sorts of ladybirds with 7 spots or 4 spots. What numbers of total spots can you make?

In this calculation, the box represents a missing digit. What could the digit be? What would the solution be in each case?

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?

Sweets are given out to party-goers in a particular way. Investigate the total number of sweets received by people sitting in different positions.

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

Try grouping the dominoes in the ways described. Are there any left over each time? Can you explain why?

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

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?

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

Dotty Six is a simple dice game that you can adapt in many ways.

This task, written for the National Young Mathematicians' Award 2016, involves open-topped boxes made with interlocking cubes. Explore the number of units of paint that are needed to cover the boxes. . . .

Can you put plus signs in so this is true? 1 2 3 4 5 6 7 8 9 = 99 How many ways can you do it?

How have the numbers been placed in this Carroll diagram? Which labels would you put on each row and column?

Find your way through the grid starting at 2 and following these operations. What number do you end on?

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.

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

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?

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

This task, written for the National Young Mathematicians' Award 2016, invites you to explore the different combinations of scores that you might get on these dart boards.

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

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

Use the interactivities to fill in these Carroll diagrams. How do you know where to place the numbers?

Find all the numbers that can be made by adding the dots on two dice.

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?

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

Leah and Tom each have a number line. Can you work out where their counters will land? What are the secret jumps they make with their counters?

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

Using the cards 2, 4, 6, 8, +, - and =, what number statements can you make?

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.

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?

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?

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

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

This project challenges you to work out the number of cubes hidden under a cloth. What questions would you like to ask?

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 hang weights in the right place to make the equaliser balance?

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?

There are 4 jugs which hold 9 litres, 7 litres, 4 litres and 2 litres. Find a way to pour 9 litres of drink from one jug to another until you are left with exactly 3 litres in three of the jugs.

Can you put the numbers 1-5 in the V shape so that both 'arms' have the same total?

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?

Jack's mum bought some candles to use on his birthday cakes and when his sister was born, she used them on her cakes too. Can you use the information to find out when Kate was born?

Can you find 2 butterflies to go on each flower so that the numbers on each pair of butterflies adds to the same number as the one on the flower?

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