# My brilliant idea - You don't sleigh?

12th December 2008 at 00:00

Maths and science - Ages 11-16

How Father Christmas delivers all his presents in one night makes an interesting maths andor science lesson.

The basics:

- Assume a population of six billion.

- Assume that there are two billion children.

- Father Christmas only delivers to about 15 per cent of all children.

- The average household has three children.

- The total time available for delivery is 31 hours.

So how many houses per minute does Father Christmas have to visit? How long does he have for each visit? Assuming that each stop is evenly distributed (0.75km per house), how many kilometres does he have to travel? And how fast would he have to travel? Why are there 31 hours for delivery available?

Having made the calculations in maths you can consider the variables that would affect such a calculation, such as:

- Why should we assume only 15 per cent of children receive presents? For example, different religions, naughtynice children.

- Do all religions have presents delivered on the same day? Some, for example, have presents on Christmas Eve or January 5.

- Which direction would Father Christmas have to travel to get 31 hours of available night time?

- How would the speed of the sleigh be affected by the weight of the presents at the startend of the trip? (Slower then faster).

- What natural forces could affect the sleigh's speed? (Air resistance, friction due to speed of sleigh through air, wind speed).

Other questionscalculationsvariables can be generated by the pupils. Problems can be made more difficult for able pupils by varying the numbers or requiring answers in smaller units, such as seconds.

Not a subscriber? Find out more about our subscription offers.
Subscribe now
Existing subscriber?
Enter subscription number