Skip over navigation
Cambridge University Faculty of Mathematics NRich logo
menu search
  • Teachers expand_more
    • Early years
    • Primary
    • Secondary
    • Post-16
    • Events
    • Professional development
  • Students expand_more
    • Primary
    • Secondary
    • Post-16
  • Parents expand_more
    • Early Years
    • Primary
    • Secondary
    • Post-16
  • Problem-Solving Schools
  • About NRICH expand_more
    • About us
    • Impact stories
    • Support us
    • Our funders
    • Contact us
  • search

Or search by topic

Number and algebra

  • The Number System and Place Value
  • Calculations and Numerical Methods
  • Fractions, Decimals, Percentages, Ratio and Proportion
  • Properties of Numbers
  • Patterns, Sequences and Structure
  • Algebraic expressions, equations and formulae
  • Coordinates, Functions and Graphs

Geometry and measure

  • Angles, Polygons, and Geometrical Proof
  • 3D Geometry, Shape and Space
  • Measuring and calculating with units
  • Transformations and constructions
  • Pythagoras and Trigonometry
  • Vectors and Matrices

Probability and statistics

  • Handling, Processing and Representing Data
  • Probability

Working mathematically

  • Thinking mathematically
  • Developing positive attitudes
  • Cross-curricular contexts

Advanced mathematics

  • Decision Mathematics and Combinatorics
  • Advanced Probability and Statistics
  • Mechanics
  • Calculus

For younger learners

  • Early Years Foundation Stage

Three Fingers and a Loop of String

Age 5 to 7
Challenge Level Yellow star
  • Problem
  • Student Solutions
  • Teachers' Resources
This is a very simple exploration of types of triangles, but can provide stimulation some interesting discussion and development of vocabulary. Asking the children to draw, compare and sort the triangles contributes to the perception and understanding of the basic properties of triangles.

Here is an example of a series of activities that could prompt the children to think about triangles and discover some of their characteristics.

Ask each child to make a triangle with his/her loop and ask several children to talk about their triangle and explain how they know it's a triangle. If responses are very vague - don't try to 'teach' a better answer yet, just move on.

Invite the children to move their fingers to create another triangle and hold it in place. Ask each child to try to find someone else who has made a triangle that looks the same.

Choose some children to explain why the triangles are the same.

Now ask the children to find someone who has a 'different' triangle, and choose some children to explain the differences.

Ask the children to form work pairs and have them make at least five different triangles, drawing each triangle on separate pieces of paper. Invite the pairs to now sort their triangle drawings into two (or more groups). Bring pairs together and have them explain their groupings to each other. Ask the foursomes to now put all their triangles together and agree on a sorting system, which can be displayed and labelled to share with the rest of the class. Finally, return to step one and ask each child to make an triangle, talk about it and explain why it's a triangle. Have they improved?

You may also like

Tangrams

Can you make five differently sized squares from the interactive tangram pieces?

Baked Bean Cans

Is there a best way to stack cans? What do different supermarkets do? How high can you safely stack the cans?

Three Squares

What is the greatest number of squares you can make by overlapping three squares?

  • Tech help
  • Accessibility Statement
  • Sign up to our newsletter
  • Twitter X logo

The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

NRICH is part of the family of activities in the Millennium Mathematics Project.

University of Cambridge logo NRICH logo