A DA P T E D F R O M M AT H I S F U N . C O M

SCIENTIFIC NOTATION

WHAT IS SCIENTIFIC NOTATION?

• Scientific notation is a special way of writing numbers• It makes it easy to write big and small numbers

Easier to write

numbers

Small number

s

Big Number

s

Scientific

Notation

BIG AND SMALL NUMBERS IN REAL LIFE

The mass of the planets and sun consist of very large numbers. For example, the sun has a mass of 1,988,000,000,000,000,000,000,000,000,000 kg

A tiny space inside a computer chip has been measured to be 0.00000256m wide, 0.00000014m long and 0.000275m high.

SCIENTIFIC NOTATION SONG

• http://www.youtube.com/watch?v=AWof6knvQwE

STRUCTURED QUESTIONS

• What are some examples of very large numbers?• What are some examples of very small numbers?

HOW DOES SCIENTIFIC NOTATION WORK?

• A number in scientific notation is written in two parts:

Just the digits (with the decimal point placed after the first digit), followed by × 10 to a power that puts the decimal point where it should be (i.e. it shows how many places to move the decimal point).

HOW DOES SCIENTIFIC NOTATION WORK?

Student Activity: Popcorn Read Aloud, students will read a paragraph and then have another student read the next paragraph for this slide.

To put a number in scientific notation, we must find both parts. To get the first part, move the decimal place of the number in order to create a number between 1 and 10.

If the number is 10 or greater, the decimal point has to move to the left, and the power of 10 will be positive.

If the number is smaller than 1, the decimal point has to move to the right, so the power of 10 will be negative:

For example in the number 400, the decimal place would move the left two decimal spaces. The number part would be 4.0

HOW DOES SCIENTIFIC NOTATION WORK?

To figure out the power of 10, think "how many places do I move the decimal point?"If the number is 10 or greater, the decimal point has to move to the left, and the power of 10 will be positive.

If the number is smaller than 1, the decimal point has to move to the right, so the power of 10 will be negative:

Example: 0.0055 would be written as 5.5 × 10-3

Because 0.0055 = 5.5 × 0.001 = 5.5 × 10-3

Example: 3.2 would be written as 3.2 × 100

We didn't have to move the decimal point at all, so the power is 100

But it is now in Scientific Notation

MORE STRUCTURED QUESTIONS

• A number in scientific notation is written in how many parts?• If a number is greater than 10, which way does

the decimal point move?• If a number is less than 10, which way does the

decimal point move?

KHAN ACADEMY VIDEO

• http://www.youtube.com/watch?v=i6lfVUp5RW8• After viewing the video, please dothe following(adapted from Save the Last WordFor Me on facinghistory.org):

• Write down a sentence of a fact from the video that particularly stood out to you in your Guided Notes. Also, write a few sentences explaining why you chose that sentence or fact.

• Divide into groups of three, labeling one student A, one B, and the other C. Invite “A”s to read one of their chosen facts. Then students B and C discuss the why student A chose that sentence or fact. After several minutes, the A students read the back of their cards (to explain why they picked the fact), thus having “the last word.” This process continues with the B student sharing and then finally student C.

INTERACTIVE ACTIVITY

• Play the game at http://www.xpmath.com/forums/arcade.php?do=play&gameid=21, try to get a minimum score of 5. Record your highest score in your Guided Notes.

FINAL QUESTIONS OF THE LECTURE

• What is 365 written in scientific notation?• Why do we use scientific notation?