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Age Range: 7-11 | 5-7
Duration: 60 or more mins
  • D & T
  • Maths
  • Science

Gear ratio

Making a gear train

Gears are used to change the speed at which something turns. A series of gears that turn each other are called a ‘gear train.’

This resource has been developed with the support of the Bugatti Trust Museum and Study Centre and focuses on the role of gears in a mechanism. The main activity involves making a series of spur gears to calculate gear ratios and see them working.

Activity: Gear ratio

In this activity learners will carry out a practical investigation to investigate how spur gears work, including calculation of simple gear ratios and assembling models of simple gear trains.

This activity could be used as a main lesson activity, to introduce the concept of gears in D&T or the practical use of ratios in maths, or as part of a project/series of lessons creating a mechanised object.

Download the free activity sheets below!

 All activity sheets and supporting resources are free to download and are fully editable, so you can tailor them to your students’ and your schools’ needs.

And please do share your learning highlights and final creations with us on social media @IETeducation or send them via email to to be featured in our online gallery.

Tools/resources required

  • Scissors
  • Glue sticks
  • Sharp pencil
  • Card and Split pins
  • Blu Tack (for piercing the card safely)
  • Cardboard (Alternative: foam board and thumb tacks)

The activity sheet includes teacher notes, guidance, useful web links, and links (where appropriate) to the national curriculum in each of the four devolved UK nations; England, Northern Ireland, Scotland, and Wales.

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