Blow Up

Instructions Level 1 Level 2 Level 3 Level 4 Level 5 Level 6   Help     More  

If the shape above is enlarged with a scale factor of 2 click on the points that
could be the centre of enlargement if the image does not reach outside the grid.

Your Image has broken out of the grid !!!

Try again with the same shape Try again with a different shape

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Click on all the points that could be the centre of enlargement of the shape if the image does not go off the grid.


Level 1 - Enlargement scale factor 2

Level 2 - Enlargement scale factor 3

Level 3 - Enlargement scale factor -1

Level 4 - Enlargement scale factor 2 without image drawing

Level 5 - Enlargement scale factor 3 without image drawing

Level 6 - Enlargement scale factor -1 without image drawing

More on Enlargements including lesson Starters, visual aids, investigations and self-marking exercises.

The phrase Blow Up has two meanings. It could me to enlarge as in “please blow up this photograph to A3 size” but it could also mean to explode. Both meanings are used in this challenge.

In Mathematics, when a shape (object) is enlarged, the position of the enlargement (image) is determined by the position of the centre of enlargement. Think of a torch (flashlight) being held at the centre of enlargement shining on the shape and casting a shadow behind it. The position of the shadow will change as the torch moves.

The objective of this challenge is to find all the dots on the grid which could possibly be the centre of enlargement if the image can be drawn completely on the grid. You will see and hear an explosion if the image created breaks out of the grid.

It is recommended the simpler Enlargements exercise (part of the Transformations exercise) is completed before taking on this challenge.

Answers to this exercise are available lower down this page when you are logged in to your Transum account. If you don’t yet have a Transum subscription one can be very quickly set up if you are a teacher, tutor or parent.

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This activity was inspired by Dr Colin Foster, Reader in Mathematics Education in the Mathematics Education Centre at Loughborough University


Before attempting this challenge you should already be good at drawing enlargements (part of the Transformations exercise). Below is an excerpt from the help video created for the Transformations exercise.

Answers to this exercise are available lower down this page when you are logged in to your Transum account. If you don’t yet have a Transum subscription one can be very quickly set up if you are a teacher, tutor or parent.

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