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This problem featured in an NRICH webinar in December 2020.

You may wish to look at Wipeout as a follow-up activity.

The Inquiry Maths website offers a related activity and explains how it can be used as an inquiry prompt in the classroom.

Here is a photo of some of the contributions offered by delegates at the ATM Conference in 2015.

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Bat Wings

Two students collected some data on the wingspan of bats, but each lost a measurement. Can you find the missing information?

Kate's Date

When Kate ate a giant date, the average weight of the dates decreased. What was the weight of the date that Kate ate?

Balancing the Books

How many visitors does a tourist attraction need next week in order to break even?

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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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