An Introduction
By definition 25 is the number you would multiply times
itself to get 25 for an answer. In other words, what times
what would give you a product of 25?
Because we are familiar with multiplication, we know that
25 = 5, because 5
x 5 = 25.
5 is the square root of 25.
By definition 49 is the number you would multiply times
itself to get 49 for an answer. In other words, what times
what would give you a product of 49?
Because we are familiar with multiplication, we know that
49 = 7, because 7
x 7 = 49.
7 is the square root of 49.
Numbers like 25 and 49, which have whole numbers for
their square roots, are called perfect
squares. You
need to memorize at least the first 15 perfect squares.
a



RADICAL – The symbol that is used to
indicate square roots.
9
is 3 because 3 times 3 is 9
Think to yourself….
WHAT TIMES WHAT will give me the
number inside the radical symbol?????

16

16
is 4 because 4 times 4 is 16.
Practice makes perfect in math!!!!
You need to memorize the first 15 perfect squares.
Copy the chart on the next slide on notebook paper.
Study it! Know it! There will be a quiz!
Perfect
square
Square root
Perfect
square
Square root
1
1 = 1
81
81 = 9
4
4 = 2
100
100 = 10
9
9 = 3
121
121 = 11
16
16 = 4
144
144 = 12
25
25 = 5
169
169 = 13
36
36 = 6
196
196 = 14
49
49 = 7
225
225 = 15
64
64 = 8