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  • Early Years Foundation Stage

Ten Green Bottles

Age 7 to 11
Challenge Level Yellow star
  • Problem
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We had very clearly explained solutions to Ten Green Bottles. David from Tithe Barn Primary School, Stockport wrote:

The answer is that the last bottle fell at five minutes to six. I worked this out by writing down the numbers 1-10 and by the first number I put the time when it fell. Then, I added 5 minute intervals and put them at the next number down i.e. 5:10, 5:15, 5:20 etc.

Jeff from Kelly Elementary School in Carlsbad, California agreed with the answer of 5.55.

Airlangga from St Joseph's Catholic Primary School wrote:

5.10 + (5minx9) = 5.55

Alistair from Histon and Impington Infant School used a similar way of working it out to David, but then generalises, leading nicely on from Airlangga's response:

I have spotted that the equation for the nth bottle is 5 x(n-1) minutes after 5.10

Very well thought out all of you.

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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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