This activity challenges you to decide on the 'best' number to use in each statement. You may need to do some estimating, some calculating and some research.

How could you estimate the number of pencils/pens in these pictures?

Four Go game for an adult and child. Will you be the first to have four numbers in a row on the number line?

What do you notice about the date 03.06.09? Or 08.01.09? This challenge invites you to investigate some interesting dates yourself.

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

This challenge is a game for two players. Choose two numbers from the grid and multiply or divide, then mark your answer on the number line. Can you get four in a row before your partner?

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

Make an estimate of how many light fittings you can see. Was your estimate a good one? How can you decide?

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

There are four equal weights on one side of the scale and an apple on the other side. What can you say that is true about the apple and the weights from the picture?

Mr. Sunshine tells the children they will have 2 hours of homework. After several calculations, Harry says he hasn't got time to do this homework. Can you see where his reasoning is wrong?

The Man is much smaller than us. Can you use the picture of him next to a mug to estimate his height and how much tea he drinks?

Dicey Operations for an adult and child. Can you get close to 1000 than your partner?

Unmultiply is a game of quick estimation. You need to find two numbers that multiply together to something close to the given target - fast! 10 levels with a high scores table.

Who said that adding, subtracting, multiplying and dividing couldn't be fun?

Find the exact difference between the largest ball and the smallest ball on the Hepta Tree and then use this to work out the MAGIC NUMBER!

Can you deduce the pattern that has been used to lay out these bottle tops?

How might you use mathematics to improve your chances of guessing the number of sweets in a jar?