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Hello, Natasha!

This is Mrs. Bisanz. I will be your teacher today!

OUR LESSON: Powers and Exponents

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Warm Up

1.List all the factors of 35. 1, 5, 7,

2.Is 120 divisible by 8? Yes 15 x 8 = 120

3.What is 52.35 x 12.5 = 654.375

4.82.001 – 34.9 = 47.101

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Lets us review about Factors

A whole number that divides exactly into another whole number is called a factor of that number.

For example 100 /25 = 4 So, 25 is a factor of 100

20 / 4 = 5 So, 4 is a factor of 20

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If a number can be expressed as a product of two whole numbers, then the whole numbers are called factors of that number.

20 = 1 x 20 = 2 x 10 = 4 x 5

So, the factors of 20 are 1, 2, 4, 5, 10 and 20.

Revision

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Lets get Started with Powers and Exponents

If you recall we used exponents while representing numbers in scientific notations like

5 x 103 = 5000

So 10 to the power of 3 is 10 x 10 x 10 = 1000

And 5 x 1000 = 5000

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The exponent is sometimes referred to as the power.

46 Base Exponent

Powers and Exponents

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46 means to multiply the base 4 by itself 6 times

Let us understand what does 46 mean ?

46 = 4 x 4 x 4 x 4 x 4 x 4

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So if we change the exponents we get

1.) 46 = 4x4x4x4x4x42.) 43 = 4 x 4 x 43.) 41 = 44.) 40 = 1

Exponents

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Now -a x -a x -a = -a3

and a x a x b x a x b x c = a3b2c

Remember –(3)4 = (-3)4/

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Lets us take some more examples

1. 2 • 2 • 2 • 2 • 2 • 2 • 2 =2. (-3) (-3) (-3) (-3) =

3. a • m • m • a • m  • a • a =4. p • 2 • r • r • r  • p • 2 =

27

(-3)4

a4 m3

22 p2 r3

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Now you try some examples

a x a x a = a3

2 x 2 x b x b x 6 x 6 = 22b262

-3 x -3 x c x c x -3 = (-3)3c2

2x3 + 4y (x = -2 ; y = 3) =192

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Break

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1.Which option will you take if you are given to choose between $1000 or doubling your dollars each day for 10 days ?

Option 2 = 1 + 2 + 4 + 8 + 16 + 32 + 64 + 128 + 256 + 512 = 1023

So option 2 is better

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2. A boy gets 80 marks in two subjects and 73 marks in three subjects. What is his final score?

802 + 733 = 379

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3. Evaluate

1) (2+3)2 – (-3)2 - (2)4 = 0

2) (ab)3 - (ac)3 = (-243)

if a = -3, b = 2 and c = -1

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Lets review what we have learnt today

26

Base

Exponent or Power

Here 2 is the Base and 6 is the Power of 2

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26 = 2 x 2 x 2 x 2 x 2 x 2 and 20 = 1

Any number to the power 0 is equal to 1

26 can be written as

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Great Job Today!

Remember to practice what you have learned!