Using Scientific Notation in Multiplication and Division

Lesson Two and

Lesson Three

WARM UP 

1. A rectangle has a length of  and a width of .  What is the expression for the area of the rectangle?

 3. -4(3)

 4.

5. Write  0.0000000809 in scientific notation.

EXAMPLE ONE

• GIVEN: (2.93 X 10-2) • (8.3 X 10-5)

• MULTIPLY DECIMALS: 2.93 X 8.3 = 24.319

• ADD EXPONENTS: 10-2 X 10-5=10-2+(-5)=10-7

• ANSWER: 24.319 X 10-7

• REWRITE IN SCIENTIFIC NOTATION

• FINAL ANSWER: 2.43 X 10-6

EXAMPLE TWO

• GIVEN: 3.42 X 105 • 4.67 X 109

• MULTIPLY DECIMALS: 3.42 X 4.67 = 15.97

• ADD EXPONENTS: 105 X 109=105+9=1014

• PRELIMINARY ANSWER: 15.97 X 1014

• NOW, REWRITE IN SCIENTIFIC NOTATION IF NEEDED.

• FINAL ANSWER: 1.597 X 1015

Let’s try three together……

(2 x 103) • (3 x 105)

(3.2 x 10-5) x (1.5 x 10-3)

((9.2 x 105) x (2.3 x 107)

CLASSWORK

Work with your partner to complete the scientific notation worksheet using multiplication.

HOMEWORK

Complete the scientific notation worksheet using multiplication. Show all your work.

WARM UP

1. A sack of cocoa beans weighs about 132 lbs. How much would one thousand sacks of cocoa beans weigh? Write the answer in scientific notation.

2. (3.5 x )(4 x )

3.

4. Explain the difference between (-2)³ and -

5. Simplify: (-3)(4)

EXAMPLE THREE

• GIVEN: 3.45 X 102 1.23 X 10-5

• DIVIDE DECIMALS: 3.45 ÷ 1.23= 2.81

• SUBTRACT EXPONENTS: 2- (-5) = 7

• REWRITE IN SCIENTIFIC NOTATION IF NEEDED

• ANSWER: 2.81 X 107

EXAMPLE FOUR

• GIVEN: 8 • 10-3

2 • 10-2

• DIVIDE THE WHOLE NUMBERS:

• SUBTRACT EXPONENTS: (-3)-(-2)= -1

• REWRITE IN SCIENTIFIC NOTATION IF NEEDED

• FINAL ANSWER: 4 •10-1

Let’s try three together…..

(8 • 106) ÷ (2 • 103) (5.76 x 102) ÷ (4.55 x 10-4)

(8.2 x 10-6) / (9.4 x 10-3)

CLASSWORK

With your partner, work through the division problems. Show all your work.

On a sheet of paper, complete the following two problems. Show all your work. Hand your work in for a grade.

1. A football field is 1.20 x yards by 5.33 x yards. What is the approximate area of the football field?

HOMEWORK

Complete the scientific notation worksheet using division. Show all your work.

Need help? Watch the following videos.

www.youtube.com/watch?v=ciFOlirz4Js

Scientific Notation: multiplication/division

Scientific Notation: https://www.youtube.com/watch?v=GD5LbqSqKys