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

Doughnut Percents

Age 7 to 14
Challenge Level Yellow starYellow star
Primary curriculum
Secondary curriculum
  • Problem
  • Student Solutions
  • Teachers' Resources


This is one of a series of problems designed to develop students' team working skills. Other tasks in the series can be found by going to this article.

Doughnut Percents - printable dominoes
Doughnut Percents - printable rule cards 
Doughnut Percents - printable hint cards

Cards image
 

What are you aiming to do?

Every member of the team must end up with a set of four dominoes which join together to form a "doughnut" where touching ends have equal value. For example:

Doughnut e.g.


The task is only successfully completed when everyone on the team has completed their domino doughnut.

You will need to work in a team of four. If you have a fifth person available - use them as an observer (see guidance below).
 

How to play

In silence, distribute the 16 domino cards randomly amongst the team (four cards each).

Players pass dominoes to other team members in order to help one another complete their doughnut.

  • Each member of the team starts with four dominoes in front of them.
  • The dominoes in front of each person should be visible to everyone.
  • Team members can only give dominoes; they cannot take dominoes from someone else.
  • Each team member must have at least two dominoes in front of them at all times.
  • No one can talk or give non-verbal signals to other members of the team.

Use an observer to check that the team obeys the rules and to keep a record of when members of the team help someone else (rather than, for example, when they just pass a piece on without looking at what the other person or team actually needs).

Observers can place one of the hint cards in the middle, if after a period of five minutes the team is not making any progress.

  • 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