Teacher's Skills Tests For Dummies
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The Table of Joy is a handy tool for working out percentages, ratios, conversions and much else besides! Here’s an example how you can use it to convert 300 miles into kilometres, using the fact that 5 miles is roughly 8 kilometres:

  1. Draw out a big noughts and crosses style grid.

  2. Leave the top-left square blank and label the rest of the top row with the things you’re converting: in this case, miles and kilometres.

  3. Again, leaving the top-left square blank, label the rest of the leftmost column with the information you have: the conversion rate and the distance you’re converting.

  4. Put the numbers you know in the logical places: 5 in the rate/miles square, 8 in the rate/kilometres square and 300 in the distance/miles square.

  5. Now shade the grid like a chessboard. Multiply the two numbers in the same-coloured spaces, and divide by the other. Here, it’s 300 x 8 ÷ 5 = 480km.

About This Article

This article is from the book:

About the book authors:

Colin Beveridge holds a doctorate in mathematics from the University of Saint Andrews and is a full-time maths tutor.
Andrew Green studied for his doctorate at Brunel University and is currently a senior lecturer in Education.

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