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The Pet Graph

Age 7 to 11
Challenge Level Yellow star
  • Problem
  • Getting Started
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Tina sent us her solution. She tackled the problem logically.

Only one child has a parrot at home, so the green bar must be parrots.

Fish+gerbils=dogs and if you try all the possibilities it must be the red bar for dogs, and the blue and yellow bars for fish and gerbils (but we don't know which way round yet).

There are two less cats than dogs, so the purple bar must be for cats (because we know how many dogs there are now).

So the orange bar must be for hamsters (because all the rest have been matched up, even though we don't know which way round blue and yellow are yet).

There are twice as many fish as hamsters, so the yellow bar must be for fish. So the blue bar must be for gerbils.

There are half the number of gerbils as there are cats- yes, this works!

During lockdown 2020 we received the following from Clemmie who goes to Thomas's London Day Schools.

Well done Clemmie, that solution is very well shown in your work.

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How Big Are Classes 5, 6 and 7?

Use the two sets of data to find out how many children there are in Classes 5, 6 and 7.

Presenting the Project

Have a look at all the information Class 5 have collected about themselves. Can you find out whose birthday it is today?

Real Statistics

Have a look at this table of how children travel to school. How does it compare with children in your class?

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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.

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