SME
Grade 8 Math · Problem type
Rational or irrational?
Use this for “Which of these numbers are irrational: −11/4, 0.2468, √41, −√81?”
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Is the number rational or irrational?
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Assumptions
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A rational number is a fraction of whole numbers (or its opposite). Its decimal ends or repeats.
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The square root of a perfect square is whole, so it is rational: √81 = 9.
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The square root of any other whole number is irrational, and so is π.
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