Square Roots and
Irrational Numbers
Squares and Roots
2
2
2
2
2
2
2
2
2
2
2
2
1 1
2 4
3 9
4 16
5 25
6 36
7 49
8 64
9 81
10 100
11 121
12 144












1 1
4 2
9 3
16 4
25 5
36 6
49 7
64 8
81 9
100 10
121 11
144 12












Squares and Roots
2
2
2
2
2
2
2
2
2
2
2
2
1 1
2 4
3 9
4 16
5 25
6 36
7 49
8 64
9 81
10 100
11 121
12 144












1 1
4 2
9 3
16 4
25 5
36 6
49 7
64 8
81 9
100 10
121 11
144 12












Squares and Roots
2
2
2
2
2
2
2
2
2
2
2
2
1 1
2 4
3 9
4 16
5 25
6 36
7 49
8 64
9 81
10 100
11 121
12 144












1 1
4 2
9 3
16 4
25 5
36 6
49 7
64 8
81 9
100 10
121 11
144 12












Note!!!
Notice that squares and square roots are
inverses (opposites) of each other.
Note!!!
Notice that squares and square roots are
inverses (opposites) of each other.
Note!!!
Notice that squares and square roots are
inverses (opposites) of each other.
Note!!!
Notice that squares and square roots are
inverses (opposites) of each other.
Note!!!
Notice that squares and square roots are
inverses (opposites) of each other.
Note!!!
Notice that squares and square roots are
inverses (opposites) of each other.
Note!!!
Notice that squares and square roots are
inverses (opposites) of each other.
Estimating Square Roots
Once you memorized squares and their
roots, we can estimate square roots that
are not perfect squares
 For example, what about 8
Estimating Square Roots
 We find the two perfect squares that are before
and after the square root of 8. . .
 and
 Look at them on a number line:
4
9
5
4
9
6 7 8
3
2
2 3
Estimating square roots
 We can see that is between 2 and 3 but
is closer to 3. We would say that is
approximately 3.
4 5 9
6 7 8
3
2
2 3
8
8
TRY THIS:
Estimate to the nearest whole number
27
78

50
Click to the next slide to see if you are right!
TRY THIS:
Estimate to the nearest whole number
27
78

50
5
-9
7
 Rational number- can be written as
a fraction
 Irrational number- cannot be written
as a fraction because:
•it is a non-terminating decimal
•it is a decimal that does NOT repeat
* The square roots of ALL perfect
squares are rational.
* The square roots of numbers that are
NOT perfect squares are irrational.
Try This: Identify each number as
rational or irrational
2
81

0.53
0.627
13.875931...
Identify each number as rational or
irrational.
2
81

0.53
0.627
13.875931...
Irrational
Rational
Rational
Rational
Irrational
Identify each number as rational or
irrational.
2
81

0.53
0.627
13.875931...
Irrational
Rational
Rational
Rational
Irrational
Identify each number as rational or
irrational.
2
81

0.53
0.627
13.875931...
Irrational
Rational
Rational
Rational
Irrational
Identify each number as rational or
irrational.
2
81

0.53
0.627
13.875931...
Irrational
Rational
Rational
Rational
Irrational

Irrationalizingism numberismsssssss 2.ppt

  • 1.
  • 2.
    Squares and Roots 2 2 2 2 2 2 2 2 2 2 2 2 11 2 4 3 9 4 16 5 25 6 36 7 49 8 64 9 81 10 100 11 121 12 144             1 1 4 2 9 3 16 4 25 5 36 6 49 7 64 8 81 9 100 10 121 11 144 12            
  • 3.
    Squares and Roots 2 2 2 2 2 2 2 2 2 2 2 2 11 2 4 3 9 4 16 5 25 6 36 7 49 8 64 9 81 10 100 11 121 12 144             1 1 4 2 9 3 16 4 25 5 36 6 49 7 64 8 81 9 100 10 121 11 144 12            
  • 4.
    Squares and Roots 2 2 2 2 2 2 2 2 2 2 2 2 11 2 4 3 9 4 16 5 25 6 36 7 49 8 64 9 81 10 100 11 121 12 144             1 1 4 2 9 3 16 4 25 5 36 6 49 7 64 8 81 9 100 10 121 11 144 12            
  • 5.
    Note!!! Notice that squaresand square roots are inverses (opposites) of each other.
  • 6.
    Note!!! Notice that squaresand square roots are inverses (opposites) of each other.
  • 7.
    Note!!! Notice that squaresand square roots are inverses (opposites) of each other.
  • 8.
    Note!!! Notice that squaresand square roots are inverses (opposites) of each other.
  • 9.
    Note!!! Notice that squaresand square roots are inverses (opposites) of each other.
  • 10.
    Note!!! Notice that squaresand square roots are inverses (opposites) of each other.
  • 11.
    Note!!! Notice that squaresand square roots are inverses (opposites) of each other.
  • 12.
    Estimating Square Roots Onceyou memorized squares and their roots, we can estimate square roots that are not perfect squares  For example, what about 8
  • 13.
    Estimating Square Roots We find the two perfect squares that are before and after the square root of 8. . .  and  Look at them on a number line: 4 9 5 4 9 6 7 8 3 2 2 3
  • 14.
    Estimating square roots We can see that is between 2 and 3 but is closer to 3. We would say that is approximately 3. 4 5 9 6 7 8 3 2 2 3 8 8
  • 15.
    TRY THIS: Estimate tothe nearest whole number 27 78  50 Click to the next slide to see if you are right!
  • 16.
    TRY THIS: Estimate tothe nearest whole number 27 78  50 5 -9 7
  • 17.
     Rational number-can be written as a fraction  Irrational number- cannot be written as a fraction because: •it is a non-terminating decimal •it is a decimal that does NOT repeat * The square roots of ALL perfect squares are rational. * The square roots of numbers that are NOT perfect squares are irrational.
  • 18.
    Try This: Identifyeach number as rational or irrational 2 81  0.53 0.627 13.875931...
  • 19.
    Identify each numberas rational or irrational. 2 81  0.53 0.627 13.875931... Irrational Rational Rational Rational Irrational
  • 20.
    Identify each numberas rational or irrational. 2 81  0.53 0.627 13.875931... Irrational Rational Rational Rational Irrational
  • 21.
    Identify each numberas rational or irrational. 2 81  0.53 0.627 13.875931... Irrational Rational Rational Rational Irrational
  • 22.
    Identify each numberas rational or irrational. 2 81  0.53 0.627 13.875931... Irrational Rational Rational Rational Irrational