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Lesson 9-1 Pages 436-440. Squares and Square Roots. Read Pages 436-438. PA Lesson Check 7-Ch7. What you will learn!. How to find squares and square roots. How to estimate square roots. Vocabulary. What you really need to know!. A perfect square is the square of a whole number.
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Lesson 9-1Pages 436-440 Squares and Square Roots Read Pages 436-438 PA Lesson Check 7-Ch7
What you will learn! • How to find squares and square roots. • How to estimate square roots.
What you really need to know! A perfect squareis the square of a whole number. A square rootof a number is one of two equal factors of the number.
What you really need to know! Every positive number has a positive square root and a negative square root. The square root of a negative number such as –25, is not real because the square of a number is never negative.
Square Square Root
Example 1: Find the square root: Since 82 = 64,
Example 1b: Find the square root: Since 112 = 121,
Example 1c: Find the square root: Since 22 = 4 and (-2)2 = 4,
Example 2: Use a calculator to fine the square root to the nearest tenth. 4.8
Example 2b: Use a calculator to fine the square root to the nearest tenth. -6.8
Example 3: Estimate the square root to the nearest whole number. The perfect squares are: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, ...
22 is between 16 and 25. The perfect squares are: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, ...
22 is closer to 25. So 5 is the best estimate for the square root of 22. The perfect squares are: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, ...
Example 3b: Estimate the square root to the nearest whole number. The perfect squares are: ..., 169, 196, 225, 256, 289, 324, 361, ...
319 is between 289 and 324. The perfect squares are: ..., 169, 196, 225, 256, 289, 324, 361, ...
319 is closer to 325. So 18 is the best estimate for the square root of 319. The perfect squares are: ..., 169, 196, 225, 256, 289, 324, 361, ...
Example 4: To estimate how far you can see from a point above the horizon, you can use the formula: where D is the distance in miles and A is the altitude, or height, in feet.
Example 4: The observations deck at the Seattle Space Needle is 520 feet above the ground. On a clear day, about how far could a tourist see? Round to the nearest tenth.
Page 438 Guided Practice #’s 4-11
Read: Pages 436-438 with someone at home and study examples!
Homework: Pages 439-440 #’s 12-56 even, 71-80 Lesson Check 9-1
Homework: Pages 439-440 #’s 12-56 even #’s 59, 60 and 71-74
Page 745 Lesson 9-1