Download Scientific Notation

8.5
Scientific Notation
What was the price of Alaska per square mile?
Goal
Read and write numbers
in scientific notation.
In 1867 the United States
purchased Alaska by writing a
check for $7.2 million. In
Example 5 you will use
scientific notation to find the
price per square mile of
that purchase.
Key Words
• scientific notation
Numbers such as 100, 14.2, and 0.07 are written in decimal form. Scientific
notation uses powers of ten to express decimal numbers. A number is written
in scientific notation if it is of the form c 10n where 1 ≤ c < 10 and n is an
integer. Here are three examples.
1.2 103 1.2 1000 1200
5.6 100 5.6 1 5.6
3.5 101 3.5 0.1 0.35
Student Help
STUDY TIP
When multiplying by
10n and n > 0, move
the decimal point n
places to the right.
When n < 0 move the
decimal point n places
to the left.
EXAMPLE
1
Write Numbers in Decimal Form
Write the number in decimal form.
a. 2.83 101
c. 8 101
b. 4.9 105
d. 1.23 103
Solution
a. 2.83 101 28.3
Move decimal point 1 place to the right.
b. 4.9 105 490 000
Move decimal point 5 places to the right.
c. 8 101 0.8
Move decimal point 1 place to the left.
d. 1.23 103 0.00123
Move decimal point 3 places to the left.
Write Numbers in Decimal Form
Write the number in decimal form.
1. 2.39 104
2. 1.045 107
3. 3.7 108
4. 8.4 106
5. 1.0 102
6. 9.2 108
8.5
Scientific Notation
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