Digits, Grade 8, Volume 1, Homework Helper

1-2: Approximating Irrational Numbers

Key Concept

Show square root of 2 as a decimal.

First, label the square roots you know on a number line. square root of 2 is between 1 and 2, but it's a little closer to 1 than 2.

A number line.

square root of 2 must be between 1.4 and 1.5.

A number line. 1.4 = radical 1.96. 1.5 = radical 2.25. Radical 2 is between 1.4 and 1.5, closer to 1.4.

square root of 2 is somewhere between 1.41 and 1.42.

A number line. 1.41 = radical 1.9881. 1.42 = radical 2.0164. Radical 2 is between 1.41 and 1.42.

There is no exact decimal expansion for square root of 2 , but you can find one that is a pretty good approximation.

A number line with radical 2 between 1.41421356 and 1.41421357.


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Table of Contents

Digits, Grade 8, Volume 1, Homework Helper Unit A: Number and Operations Unit B: Proportionality Unit C: Expressions, Equations, and Relationships English/Spanish Glossary Formulas Math Symbols Formulas Measures Properties