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Between Two Whole Numbers

Part of the Numbers & Operations section of Coddy's Pre-Algebra journey. Lesson 41 of 57.

Most whole numbers are not perfect squares, so their roots are not whole. You can still say where such a root lies. Take 50\sqrt{50}: 50 sits between the perfect squares 49 and 64, so 50\sqrt{50} sits between their roots, 7 and 8.

Why does that work? A bigger number always has a bigger root, so the order is kept. Since 49<50<6449 < 50 < 64, the roots line up the same way: 49<50<64\sqrt{49} < \sqrt{50} < \sqrt{64}, which is 7<50<87 < \sqrt{50} < 8.

You can even tell which end it is nearer. 50 is just 1 past 49 and 14 short of 64, so 50\sqrt{50} is only a little more than 7. A calculator says about 7.07.

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This lesson includes a short quiz. Start the lesson to answer it and track your progress.

quiz iconTest yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Numbers & Operations