Shape Times Shape
These eleven shapes each stand for a different number. Can you use the number sentences to work out what they are?
Problem
Shape Times Shape printable sheet
The coloured shapes stand for eleven of the numbers from 0 to 12. Each shape is a different number.
Can you work out what they are from the multiplications below?
For accessibility, clicking on the 'show' button below will show a description of this image.
Square × square × square = semicircle
Square × oval = semicircle
Oblong × oval = circle
Oblong × square = equilateral triangle
Equilateral triangle × square = circle
Square × square = oval
Oblong × oblong = eight-pointed star
Square × five-pointed star = hexagon
Oblong × rhombus = oblong
Rhombus × hexagon = hexagon
Square × isosceles triangle = isosceles triangle
Isosceles triangle × semicircle = isosceles triangle
Click here for a poster of this problem.
You may be interested in the other problems in our Number Fluency Feature.
Getting Started
Where could you start?
What can you tell from the first multiplication with three purple squares and a yellow semi-circle?
Perhaps you can use what you now know to help you with another calculation?
How will you remember what you have tried and what you have found out? You could use this sheet to keep a note of what you think the shapes stand for.
Teachers' Resources
Shape Times Shape
Shape Times Shape printable sheet
The coloured shapes stand for eleven of the numbers from 0 to 12. Each shape is a different number.
Can you work out what they are from the multiplications below?
Click here for a poster of this problem.
You may be interested in the other problems in our Number Fluency Feature.
Using NRICH Tasks Richly describes ways in which teachers and learners can work with NRICH tasks in the classroom.
Why do this problem?
Possible approach
As you circulate, listen out for clear reasoning, based on learners' knowledge of number properties. You may wish to warn some pairs that you will be asking them to share their thinking with everyone later. It would be worth stopping everyone for a brief mini plenary before that if you notice some interesting and efficient ways to record.
Tamara Pearson, a teacher from Atlanta, US, wrote to us to say she had adapted this task and created her own version using Adinkra symbols. Thank you, Tamara.
Key questions
What does that tell us? How do we know?
Possible extension
Possible support
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