Chapter 1 - Introduction to Algebraic Expressions - 1.4 Positive and Negative Real Numbers - 1.4 Exercise Set - Page 36: 101

Since $\sqrt(2)$ is an irrational number, it has an infinite number of decimal places. The calculator cannot show all of these, so it rounds the answer. Hence, the decimal value on the calculator is not exact. Thus, when you square this value, it is not exactly equal to 2.

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