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

More Numbers in the Ring

Age 5 to 7
Challenge Level Yellow starYellow starYellow star
Primary curriculum
  • Problem
  • Getting Started
  • Student Solutions
  • Teachers' Resources

More Numbers in the Ring

More Numbers in the Ring printable sheet

Three blank squares joined in a ringBefore doing this problem, it would be a good idea to look at Ring a Ring of Numbers.

Change the ring so that there are only three squares.
Can you place three different numbers in them so that their differences are odd?
Can you make the differences even?
What do you notice about the sum of each pair in each case?

Try with different numbers of squares around the ring.
What happens with 5 squares? 6 squares?
What do you notice?

This problem is based on an idea taken from "Apex Maths Pupils' Book 2" by Ann Montague-Smith and Paul Harrison, published in 2003 by Cambridge University Press.

Why do this problem?

This problem builds on Ring a Ring of Numbers. It encourages children to start from different examples and then begin to draw some more general conclusions based on their understanding of odd and even numbers.

Key questions

What happens when you put one more number in the ring?
What happens when you put two more numbers in the ring?
What happens when there is an odd number of numbers in the ring?
What happens when there is an even number of numbers in the ring? 

Possible extension

The problem Number Differences makes a good follow-up challenge.

Possible support

Some children will benefit from spending more time on the Ring a Ring of Numbers problem. Having digit cards to move around on a large piece of paper will also help and pupils might benefit from having sheets of blank rings so that they can try different combinations of numbers:

Sheet with 3-number rings
Sheet with 4-number rings
Sheet with 5-number rings
Sheet with 6-number rings

You may also like

I'm Eight

Find a great variety of ways of asking questions which make 8.

Let's Investigate Triangles

Vincent and Tara are making triangles with the class construction set. They have a pile of strips of different lengths. How many different triangles can they make?

Noah

Noah saw 12 legs walk by into the Ark. How many creatures did he see?

  • 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