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

Criss Cross Quiz

Age 7 to 11
Challenge Level Yellow star
  • Game

A game for two players. Practices subtraction or other maths operations knowledge. Uses coordinate geometry to locate the numbers used.

You Will Need:

  • A copy of the game board
  • 25 circles with the numbers from 6 to 30 (inclusive) written on them
  • A pencil and paper

Getting ready to play:

Using all of the numbers from 6 to 30, write a different number on one of the circles on the game board.

Don't write the numbers in counting order, write them randomly in the circles.

To help keep track, as you use a number, cross it out from the bottom circles.

You may not use the same number twice.

Make sure your opponent can't see your game board.

Decide who will go first and who will be second.

The aim:

To gain as many points as possible by answering maths facts problems.

To play:

  • Choose a coordinate to locate a circle and number on your opponent's board. (For example, I might call C,4. Always call the letter before the number. Both myself and my opponent then find the circle on our board where the lines C and 4 cross each other.)
  • Each player calls out the number that has been written on the called circle (at C,4 in my example).
  • Find the difference between the smaller number and the larger number.
  • Score 2 for a correct answer.
  • Cross out the number circle you have just used. It can't be used again.
  • If both your and your opponents circles have the same number in them, cross out the numbers but score 0.
  • Whoever called the greater of the two numbers used gets a bonus of 5.
  • Score 0 for an incorrect answer, and get no bonus award for having the greater number.
  • Keep a running total of your score on your paper.
  • Keep playing until all the circles are crossed out.
  • The player with the highest score wins.

Variations:

Keeping the board and numbers the same, addition can be the operation practiced. If practice is needed in multiplication, the given numbers can be altered according to the facts that need to be worked on.

Increasing the value of the chosen numbers or choosing a smaller set of lower numbers and repeating them will allow the level of difficulty to be matched to the skill level of the players.

You may also like

Prompt Cards

These two group activities use mathematical reasoning - one is numerical, one geometric.

Consecutive Numbers

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.

Exploring Wild & Wonderful Number Patterns

EWWNP means Exploring Wild and Wonderful Number Patterns Created by Yourself! Investigate what happens if we create number patterns using some simple rules.

  • 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