As Ben and Katie don white coats to enter the production area of a chocolate factory, Ben regales Katie with some amazing facts about large and small numbers.

00.57-01.33

Touring the factory, the production lines roll and huge numbers of familiar sweets rush past as Ben and Katie discover some interesting numerical facts about production on this scale.

01.33-03.42

Ben introduces standard form, as a 'neat shorthand' for dealing with all the noughts in these kinds of numbers. He and Katie explain how both very large and very small numbers are written in this form. A demonstration shows how the digits move to the left or right when multiplying or dividing by powers of 10.

03.42-04.28

The numbers found at the chocolate factory are converted to standard form. Ben and Katie want to know how to write 21 thousand million (the number of Smarties produced in a year) in standard form.

04.28-06.21

Katie uses the minute quantities of Vitamin E contained in chocolate to work through a problem involving multiplication of numbers in standard form.

Leaving the factory, Ben is disappointed that he must return the goodies he has secreted about his person.

06.21-07.42

Ben visits Jodrell Bank to see how astronomers use standard form to process information from giant satellite dishes. Taking 1m to represent the distance from the Earth to the Sun, Ben shows what the relative distances of Pluto and of Pioneer 10 would be.

07.42-10.19

The astronomer Karen Wills describes her work with a distant galaxy that is '9 with 22 zeros after it' metres away, and how she needs to use standard form to work with such figures. Ben and Karen show how to calculate the time taken for light from that galaxy to reach the Earth: this involves division of numbers in standard form. The answer shows that we are seeing the galaxy as it was 10 million years ago.

10.19-13.23

In 'Tick or Trash', Ben and Katie tackle an exam question involving multiplication of numbers given in standard form. Katie's error in multiplying the indices leads to further discussion of the techniques that students need to remember.

13.23-end

Ben and Katie reiterate the key points to remember when calculating with numbers given in standard form.