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How to use a scale factor to work out new dimensions and enlarge different shapes is explained through real-life scenarios in this video for use in KS4 maths lessons.

Dave has cut two pieces of cake for himself and Fran, but cannot work out why Fran says his is eight times larger when all the sides are only twice the length of hers.

Dave then tries to help a dance school enlarge a logo and paint it on some t-shirts. He successfully enlarges the logo using a scale factor of three, but can't work out why, when he comes to paint the design on the t-shirt, he quickly runs out of ink.

Back in the studio, Fran demonstrates the relationship between length and area scale factors and suggests that maybe that was why Dave may not have had enough ink.

Finally, the t-shirts are painted and the dance group are happy, and so is Dave, when he finally works out why his cake is eight times bigger than Fran's.

Published : May 2010

15 mins


Inside Maths


Secondary Pupil


Secondary Maths

Geometry and measures


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