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Grade 8:  The Learning Equation Math

11.05 Square Root

Number Concepts

Refresher pp 10-11

Learning Outcomes:

The student will:

Relaltionship between Squares and Square Root

 

Small Squares in Area of a Square Square Root of Area
4 2
9 3
16 4
25 5
36 6
49 7
64 8
81 9
100 10

 

Click or .  If you then click , the answer is moved to the first input box.  Try entering your own values to see the relationship between square and square root.

 

Area of Square
(cm2)
 Square Root Calculation
8 8 wpeBF.jpg (760 bytes)
18 18 wpeBF.jpg (760 bytes)
28 28 wpeBF.jpg (760 bytes)
58 58 wpeBF.jpg (760 bytes)
78 78 wpeBF.jpg (760 bytes)
108 108 wpeBF.jpg (760 bytes)
208 208 wpeBF.jpg (760 bytes)
10008 10008 wpeBF.jpg (760 bytes)

Estimate the square root:
Number
 Quick Estimate Estimate
281
 
10 x 10 = 100
15 x 15 = 225
20 x 20 = 400

Since 281 is closer to 225, a good estimate is 15.
Nearest 1:
15 x 15 = 225
16 x 16 = 256
17 x 17 = 289

Since 281 is closer to 289, the best estimate is 17.
0.44
Nearest 0.1:
0.5 x 0.5 = 0.25
0.6 x 0.6 = 0.36
0.7 x 0.7 = 0.49
Since 281 is closer to 0.49, the best estimate is 0.7.

 

Compute the square root using the calculator above:
Number
 Square Root Calculation Square Root (hundredth)
8 8 wpeBF.jpg (760 bytes) 2.83
18 18 wpeBF.jpg (760 bytes) 4.24
50.25 50.25 wpeBF.jpg (760 bytes) 7.09
120.36 120.36 wpeBF.jpg (760 bytes) 10.97
4975.32 4975.32 wpeBF.jpg (760 bytes) 70.54

 
Review:

Square Root Flash Cards

 

Enrichment:

 

Key Terms:

square root, perfect square, natural number

Wordsearch 1101-1105

 

Pre- requisite Skills:

 

 

 

Powers and Exponents: Grade 7 Lesson 11.01

 
 

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