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

Colouring Curves Game

Age 7 to 14
Challenge Level Yellow star
  • Game
  • Teachers' Resources

Why play this game?

This game provides an opportunity for learners to consider strategy and thinking ahead. Playing the game could provide a starting point for reading about mathematical ideas such as the Four Colour Theorem.

Possible approach

The game works well when played in pairs. Learners could use pencil and paper, or perhaps whiteboards. Once everyone has had the chance to play the game a few times, the class could discuss any strategies they came up with and explain anything they noticed while playing the game.
If learners play the two colour version described at the end of the problem, they could create some intriguing images for classroom display.

Key questions

Is it better to go first or second? Does it depend on the curve?
Can you design some simple curves where you can guarantee that you will win?
What do you notice about the number of regions that meet at each vertex?
Can you come up with any strategies to help you to win?

Possible extension

The game could be investigated using various different representations for the curves - one example is a graph such as this:

curve with related graph
By using the rule that no two connected numbers can be coloured the same, learners could experiment with different curves and investigate the idea that all such curves can be coloured with just two colours.
Further investigation of these ideas at a higher level can be found in the Stage 5 problem Painting by Numbers.

Possible support

Start with some very simple curves with a small number of regions and work on the problem of how to decide whether to go first or second.

You may also like

Crossing the Bridge

Four friends must cross a bridge. How can they all cross it in just 17 minutes?

Coins

A man has 5 coins in his pocket. Given the clues, can you work out what the coins are?

Flow Chart

The flow chart requires two numbers, M and N. Select several values for M and try to establish what the flow chart does.

  • 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