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Length, Width and Area

Age 14 to 16
ShortChallenge Level Yellow star
Secondary curriculum
  • Problem
  • Solutions

The area of a rectangle is 225 square units.

Its length is 16 more than its width.

Find its width.



This problem is taken from the World Mathematics Championships
You can find more short problems, arranged by curriculum topic, in our short problems collection.

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2-digit Square

A 2-Digit number is squared. When this 2-digit number is reversed and squared, the difference between the squares is also a square. What is the 2-digit number?

Consecutive Squares

The squares of any 8 consecutive numbers can be arranged into two sets of four numbers with the same sum. True of false?

Plus Minus

Can you explain the surprising results Jo found when she calculated the difference between square numbers?

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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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