9/15/2016
Multiply
Multiplying & Dividing Numbers
in Scientific Notation
• Multiply the factors and powers of 10
separately.
– When you multiply the powers of 10, use the
product rule (keep the base and add the
exponents)
• Check that your answer is still in scientific
notation. Rewrite if needed.
5.1 ×
104
× (2.5 ×
103 )
Divide
The U.S. spends on average 1.02 × 104 dollars
per student every year. There are about
77,000,000 students in the United States.
About how much money is spent on students
each year?
(1.5 × 10−3 ) ÷ (7.5 × 102 )
• Divide the factors and powers of 10
separately.
– When you divide the powers of 10, use the
quotient rule (keep the base and subtract the
exponents)
• Check that your answer is still in scientific
notation. Rewrite if needed.
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9/15/2016
The Earth has a mass of about 1 × 1025 kg.
Neptune has a mass of 1.8 × 1027 kg.
How many times bigger is Neptune than
Earth?
Practice
6552.5 ÷ (2.5 × 102 )
(7.2 × 10−1 ) × (4 × 10−7 )
A rectangular section of wilderness will be set
aside as a new wildlife refuge. Its dimensions
are 5 × 105 meters by 4 × 104 meters. Find the
area of the new wilderness refuge.
How many times greater is the
thickness of a dime than the thickness
of a dollar bill?
How many times greater is the
diameter of the Sun than the diameter
of the Earth?
It takes the Sun about 2.3 × 108 years to orbit
the center of the Milky Way. It takes Pluto
about 2.5 × 102 years to orbit the Sun. How
many times does Pluto orbit the Sun while the
Sun completes one orbit around the Milky Way?
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