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.

A game for 2 or more players with a pack of cards. Practise your skills of addition, subtraction, multiplication and division to hit the target score.

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

This challenge extends the Plants investigation so now four or more children are involved.

The letters in the following addition sum represent the digits 1 ... 9. If A=3 and D=2, what number is represented by "CAYLEY"?

If you take a three by three square on a 1-10 addition square and multiply the diagonally opposite numbers together, what is the difference between these products. Why?

Choose four different digits from 1-9 and put one in each box so that the resulting four two-digit numbers add to a total of 100.

Find the values of the nine letters in the sum: FOOT + BALL = GAME

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

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.

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

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?

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

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

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.

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

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

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

Different combinations of the weights available allow you to make different totals. Which totals can you make?

Can you put the numbers 1 to 8 into the circles so that the four calculations are correct?

Try entering different sets of numbers in the number pyramids. How does the total at the top change?

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

Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.

Can you find six numbers to go in the Daisy from which you can make all the numbers from 1 to a number bigger than 25?

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

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

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?

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?

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

What do the digits in the number fifteen add up to? How many other numbers have digits with the same total but no zeros?

A game for 2 players. Practises subtraction or other maths operations knowledge.

Can you explain the strategy for winning this game with any target?

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?

First Connect Three game for an adult and child. Use the dice numbers and either addition or subtraction to get three numbers in a straight line.

Starting with the number 180, take away 9 again and again, joining up the dots as you go. Watch out - don't join all the dots!

In a Magic Square all the rows, columns and diagonals add to the 'Magic Constant'. How would you change the magic constant of this square?

If each of these three shapes has a value, can you find the totals of the combinations? Perhaps you can use the shapes to make the given totals?

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

Five numbers added together in pairs produce: 0, 2, 4, 4, 6, 8, 9, 11, 13, 15 What are the five numbers?

Place the digits 1 to 9 into the circles so that each side of the triangle adds to the same total.

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.

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?

Do you notice anything about the solutions when you add and/or subtract consecutive negative numbers?