N5: Perfect Squares
Outcome: Determine the square root of
perfect squares.
Sep 13­8:11
Perfect Squares: 1-400
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1x1=
2x2=
3x3=
4x4=
5x5=
6x6=
7x7=
8x8=
9x9=
10x10=
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11x11=
12x12=
13x13=
14x14=
15x15=
16x16=
17x17=
18x18=
19x19=
20x20=
Sep 13­8:11
1
Imagine a square...
• Ex. If its area is 100cm², what are its
dimesions?
• ***Remember the formula: A=b x h
• How can we represent a square with an area
of 25 cm²?
Sep 13­8:11
Activity:
• 1. I will give each of you a piece of
graph
graph paper.
• 2. Using scissors, cut out a square with an area of
any size (minimum area of 4cm²).
• 3. Write your name on the square.
• 4. On the back of the square, write the following
information:
• A) your name (again, I know. Trust me J)
• B) the dimensions of your square ex. 4cm x 4cm
• C) the area of your square ex. 16 cm²
Sep 13­8:11
2
On a sheet of looseleaf, draw
three columns:
• Name
Dimensions
area
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5cm x 5cm
25 cm²
1.Stacey
2.
3.
4.
• 29.
Sep 13­8:11
Perfect Squares:
• Definition:
A number
Sep 13­8:11
3
Are these perfect squares???
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A. 81
B. 49
C. 101
D. 36
E. 25
F. 16
G. 48
H. 324
I. 9
J. 625
K. 529
L. 1935
M. 121
N. 1.44
Sep 13­8:11
Seperate the perfect squares from the other numbers
16
2
44
24
90
88
36
100
64
81
33
13
225
169
12
Sep 14­8:06 AM
4
Give examples of square
roots…
• Definition:
a factor of a number that, when multiplied by itself, gives the original number
• Mathematicians use √ to represent only the
PRINCIPAL (POSITIVE) square root!
Sep 13­8:11
Squares and square roots are inverse
operations. If you find the square root of a
number and you square it, you end up
where you started.
• 10 x 10 =100 and so √100 = 10
• (10)²=100
and so √100=10
• *10²=10x10 and √100=10 because 100=10x10
• If we find the square root of a number and then
we square it, we are back to where we started J.
• 0.7 x.07= 0.49 and so √0.49=0.7
Sep 13­8:11
5
Fractions and decimals can also
be perfect squares J&
IF they are
VARIATIONS
Sep 13­8:11
Decimals and perfect squares:
Sep 13­8:11
6
Conversely… (by the opposite)
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A. √?=0.64
B. √?=0.0081
C. √?=0.49
D. √?=1.44
E. √?=0.25
F. √?=6.25
G. √?=0.0009
H. √?=3.6
I. √?=0.12
Sep 13­8:11
Trick with your calculator… (just
for when you verify your
answers)
• Square root
button…
• 2nd function or
inverse…
Sep 13­8:11
7
Without a calculator, calculate the following square roots.
a)√0.09
b)√0.0036
c) √0.000025
d) √2.25
Sep 15­7:50 AM
Try the following questions
WITHOUT a calculator… J
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A. √100
B. √1
C. √121
D. √4
E. √1.21
F. √0.09
G. √6.25
H. √0.0004
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I. √105
J. √1
K. √40 000
L. √4.9
M. √72
N. √14
O. √95
P. √0.4
Sep 13­8:11
8
Why isn’t the square root of 6.4
0.8???
Sep 13­8:11
• If a dance floor has an
area of 625 cm², can it be
square? Why or why not?
Sep 13­8:11
9
Why (in words) is121 a
perfect square???
• Show me (on paper) a square with an area of
0.64 cm².
Sep 13­8:11
Without a calculator…
HOW???
Sep 13­8:11
10
Without a calculator…
Are these perfect squares?
Why or why not?
Sep 13­8:11
Explain the following mistakes:
Sep 13­8:11
11
Get it??? Got it??? Good!!! J
• Book: page 11 #4, 5a-d,6, 7e-j, 8a-d,
• 9a-d,10-16
• Omit the questions with fractions… we will go
there tomorrow J.
Sep 13­8:11
Take out your homework, while I'm checking it, please
answer the following in your duotang.
Which of the following are perfect squares
a) 0.36
e) 1000
b) 0.036
c)10000
d)0.0009
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