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4-9
0.001 one thousandth
Think
10 ^2 0.01
The negative exponent indicates that the
decimal is between 0 and 1.
The number 2 indicates that the decimal
will have 2 decimal places.
1
100
1
102
Remember:Any nonzero number
with zero as an exponent equals 1.
a^0 1, a 0
Negative exponents are used
to express decimals that have
values between 0 and 1.
Update your skills. See page 407 I.
Negative Exponents
Objective To express powers with negative exponents as decimals •To express decimals as
powers with negative exponents • To simplify expressions with negative exponents
In science class, Gloria measures the length of a microorganism
as 0.001 millimeter. She knows that this length is less than
1 millimeter and greater than 0 millimeters. How can she write
this number as a power of 10?
To write 0.001 as a power of 10, rewrite the decimal as a
fraction. Apply the Law of Exponents for Division to write
a decimal as a power of 10.
0.001 Write the decimal in fraction form.
100 ^3 Apply the Law of Exponents for Division.
10 ^3
So the microorganism’s length of 0.001 millimeter is 10^3 mm.
The pattern in a place-value chart can also help you use
negative exponents to express any decimal that is a power of 10.
Write 0.00001 as a power of 10 in exponent form.
Notice that the number in each negative exponent is the same as the
number of decimal places to the right of the decimal point. Using this
pattern, you can see that 0.00001 can be expressed as 10^5.
You can write a decimal for a power
of 10 given in exponent form.
Write 10^2 as a decimal.
10 ^2 0.01
You can evaluate a power that has
any nonzero integer as the base
and a negativeexponent.
100
103
Thousands
103
Hundreds
102
Tens
101
Ones
100
Tenths
10 ^1
Hundredths
10 ^2
Thousandths
10 ^3
1000 100 10 1 0.1 0.01 0.001
1
1000
Write the numerator and the denominator as
powers of 10: 1000 10 • 10 • 10 103.
Key Concept
Negative Exponents
Any nonzero number to the negative npower can be
written as 1 divided by the number to the nth power.
For any integer nand any number a, a 0,ana^1 n.