Finding Square Roots

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3-9
Finding Square Roots
Warm Up
Problem of the Day
Lesson Presentation
Pre-Algebra
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Warm Up Find the two square roots of each
number. Evaluate each expression.
16
12
20
24
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Problem of the Day A pyramid of blocks is built
in layers. The bottom layer has 62, or 36,
blocks. The next layer has 52 blocks, and so on
until the top layer has 1 block. How many blocks
are there in all?
91 blocks
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Finding Square Roots
Learn to estimate square roots to a given number
of decimal places and solve problems using square
roots.
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Each square root is between two integers. Name
the integers.
55 is between 7 and 8.
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Each square root is between two integers. Name
the integers.
90 is between -10 and -9.
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Each square root is between two integers. Name
the integers.
80 is between 8 and 9.
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Use a calculator to find 500. Round to the
nearest tenth.
500 22.36067977.
Rounded, 500 is 22.4.
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Use a calculator to find 200. Round to the
nearest tenth.
200 14.14213562.
Rounded, 200 is 14.1.
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You want to build a fence around a square garden
that is 250 square feet. Calculate the length of
one side of the garden, round your answer to the
nearest tenth.
A s2
A 250 ft2
250 s2
15.8 ft s
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Lesson Quiz
Each square root is between two integers. Name
the two integers.
1. 27 2. 456
5 and 6
22 and 21
Use a calculator to find each value. Round to the
nearest tenth.
35.0
3. 89 4. 1223
9.4
5. A square field has an area of 2000 square
feet. To the nearest foot, how much fencing would
be needed to enclose the field?
179 ft
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Homework

• Pg 152
• 1 39 odd
• 43 55 all