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.

Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.

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

Investigate which numbers make these lights come on. What is the smallest number you can find that lights up all the lights?

What do the numbers shaded in blue on this hundred square have in common? What do you notice about the pink numbers? How about the shaded numbers in the other squares?

Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.

Ben and his mum are planting garlic. Use the interactivity to help you find out how many cloves of garlic they might have had.

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!

Find the words hidden inside each of the circles by counting around a certain number of spaces to find each letter in turn.

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?

Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?

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?

In this maze of hexagons, you start in the centre at 0. The next hexagon must be a multiple of 2 and the next a multiple of 5. What are the possible paths you could take?

How many trains can you make which are the same length as Matt's, using rods that are identical?

Use the interactivity to sort these numbers into sets. Can you give each set a name?

Frances and Rishi were given a bag of lollies. They shared them out evenly and had one left over. How many lollies could there have been in the bag?

Yasmin and Zach have some bears to share. Which numbers of bears can they share so that there are none left over?

A game for 2 or more people. Starting with 100, subratct a number from 1 to 9 from the total. You score for making an odd number, a number ending in 0 or a multiple of 6.

Mr Gilderdale is playing a game with his class. What rule might he have chosen? How would you test your idea?

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

Can you find the chosen number from the grid using the clues?

Factors and Multiples game for an adult and child. How can you make sure you win this game?

Can you work out how to balance this equaliser? You can put more than one weight on a hook.

Can you order the digits from 1-3 to make a number which is divisible by 3 so when the last digit is removed it becomes a 2-figure number divisible by 2, and so on?

An environment which simulates working with Cuisenaire rods.

Complete the magic square using the numbers 1 to 25 once each. Each row, column and diagonal adds up to 65.

How can you use just one weighing to find out which box contains the lighter ten coins out of the ten boxes?

This article for teachers describes how number arrays can be a useful reprentation for many number concepts.

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

Arrange any number of counters from these 18 on the grid to make a rectangle. What numbers of counters make rectangles? How many different rectangles can you make with each number of counters?

A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.

I am thinking of three sets of numbers less than 101. Can you find all the numbers in each set from these clues?

Imagine a wheel with different markings painted on it at regular intervals. Can you predict the colour of the 18th mark? The 100th mark?

Can you help the children in Mrs Trimmer's class make different shapes out of a loop of string?

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?

Have a go at balancing this equation. Can you find different ways of doing it?

Can you make square numbers by adding two prime numbers together?

Four of these clues are needed to find the chosen number on this grid and four are true but do nothing to help in finding the number. Can you sort out the clues and find the number?

In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?

An investigation that gives you the opportunity to make and justify predictions.

Suppose we allow ourselves to use three numbers less than 10 and multiply them together. How many different products can you find? How do you know you've got them all?

Look at the squares in this problem. What does the next square look like? I draw a square with 81 little squares inside it. How long and how wide is my square?

Use this grid to shade the numbers in the way described. Which numbers do you have left? Do you know what they are called?

In this problem we are looking at sets of parallel sticks that cross each other. What is the least number of crossings you can make? And the greatest?