Download Finding the Square of a Number

and
If a square measures 4
inches on each side, how
would you find its area?
4 inches
4 inches
4 inches
4 inches
Remember how to
calculate the area?
4 inches
4 inches
A=LXW
A = 4 in. • 4 in.
2
A = 16 in.
A square must have the
same length and width.
4 inches
4 inches
A=LxW
A = 4 in. • 4 in.
To square a number means to
multiply it by itself.
4 squared means 4 x 4
Take the number 4
And square it!
There is a shorter way to
write 4 x 4.
Say:
“4 squared” or
“4 to the 2nd power”.
This is another formula for
finding the area of a square.
s
Same or Side
A=s
2
s is the side
length
Opposites
• Squares and Square Roots are
opposites of each other. JUST LIKE>>
• Adding and Subtracting are opposites
of each other.
• Multiplying and Dividing are opposites
of each other.
The symbol used to indicate a
root is the radical symbol
Every radical expression has
three parts…
Radical
Index
2
49
Radicand
The index of a square
root is always 2.
The square root of 49 could
be written as
2
49
but, it is normally written as 49
What does square root
mean?
The square root of a number is
a number that, when multiplied
by itself, gives back the original
or same number.
What is a square root?
?
the measure of the
side of the square
25 = 5
What is the square root
of 36?
36 = 6
EXAMPLES:
Every square root has two answers. ±7
49  7
because
7  7  7  49
2
Also,
49   7 because  7  7    7   49
2
Your Turn: Give Both
Answers
• 1. √81
• 2. √121
• 3. √36
Square Roots with a
Negative on the outside
• –√49 = –7
• –√100 = –10
• –√225 = –15
Your Turn
• 1. –√25
• 2. –√144
• 3. –√121
•You may not have a
negative number
inside the square
root. It is
undefined. (√-9)
These numbers are called
perfect squares
If a number is a perfect square,
then you can find its exact
square root.
A perfect square is simply a
number that can be written as the
square of WHOLE number.
What are the first 10 whole
numbers that are perfect
squares?
2
2
2
2
2
2
2
2
2
1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10
1, 4, 9, 16, 25, 36, 49, 64, 81, 100
2
• Now, write 11²- 25²in
your notebook. You will
have a quiz on these.
•STUDY THEM:
• rewrite in your notebook,
make flash cards, make your
own quiz, etc.
•
•
•
•
•
•
•
11² = 121
12² = 144
13² = 169
14² = 196
15²= 225
16² = 256
17² = 289
18² = 324
19² = 361
20² = 400
21² = 441
22² = 484
23² = 529
24² = 576
25² = 625