User login

Shrinking Coin

Source Institutions

    Institute of Physics

Add to listGo to activity
Shrinking Coin

In this demonstration, learners attempt to get a large coin through a small hole, the size of a smaller coin. Use this activity to introduce learners to non-Euclidean geometry as the small 2D hole is stretched in 3D to produce a slit that is large enough to allow the larger coin through. Although this activity states that pounds are needed for the trick, you could easily substitute American coins. This activity guide includes a helpful video that demonstrates each step of the demo.

Quick Guide

Preparation Time:
Under 5 minutes

Learning Time:
5 to 10 minutes

Estimated Materials Cost:
1 cent - $1 per student

Age Range:
Ages 8 - adult

Resource Types:
Activity, Demonstration


Materials List (per student)

  • 1x 1p coin
  • 1x 2p coin
  • piece of paper (approx 10cm x 10 cm)
  • pencil
  • scissors


  • Mathematics
    • Geometry
      • Plane Geometry
      • Solid Geometry
  • The Nature of Science
    • The Scientific Process
      • Conducting Investigations


To use this activity, learners need to:

  • see
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


This resource is part of:

Access Rights:

  • Free access



  • All Rights Reserved, Institute of Physics,


User Lists

This resource is part of these lists: