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Copyright © Swun MathCopyright © Swun Math Grade 8 Unit 3 Lesson 5 C TE

Scientific Notation: Multiply

& Divide

Conceptual Lesson
Grade 8 · Unit 3 · Lesson 5
MC: 8 .EE. 4 

Problem of the Day

Objective: I will multiply or divide numbers expressed in scientific notation.

Vocabulary Teacher Resources

Multiplying in Scientific Notation

1. Multiply coefficients.


2. Add exponents.
   (3 × 102 ) ( 5 × 104 ) =

3 × 5 = 15

10 2+4 = 10^6

15 × 106

1.5 × 107

Proper Scientific Form

Dividing in Scientific Notation^

1. Divide coefficients.


2. Subtract exponents.

(15 × 106 ) ÷ ( 3 × 102 ) =

15 ÷3 = 5

10 6-2 = 10^4

5 × 104

Considerations:

Review exponent rules for multiplication and

division; show expanded notation. Refer to previous

lessons about scientific notation to change the

powers of ten. Show students how the expressions

can also be multiplied by changing both numbers out

of scientific notation. Use calculators to check work.

Keeping the powers of ten separate makes the

equation substantially easier and manageable

without a calculator.

Moving the decimal and making the powers of ten the

same will not make the problem easier to simplify.

Steps:

1. Check for numbers in scientific notation.


2. If multiplying-
   
   
   • Multiply coefficients.
   
   
   • Add exponents.
   
   
   
   


3. If dividing-
   
   
   • Divide coefficients.
   
   
   • Subtract exponents.
   
   
   
   


4. Write in scientific notation.

Application of MPs:

 MP2: What properties might we use to find a

solution?

A property that we might use to find a

solution can be the ____________.

 MP8: How would you prove that the solution is

correct?

I can prove that my solution is correct by

changing.

MPs

Applied MP

* Embedded MP

1 2 3 4 5 6 7 8

* ^ *

Student Journal Pages

134 - 137