The process also works in reverse. If you are doing calculations with a number
that has a lot of zeros to the right or to the left of the decimal, you can use powers
of 10 as shorthand for those values:
2,400,000 = 24 × 105
0.00037 = 37 ÷ 10^5 = 37 × 10 –5
Let’s look at a GRE-style example:
(1.9)(2 × 10^6 )
190,000 =?
A 0.02
B 0.2
C 2
D 20
E 200
SOLUTION: To make the calculations easier, express the denominator as
1.9 × 105. The fraction now reads:
(1.9)(2 × 10^6 )
1.9 × 10^5
SOLUTION: Divide numerator and denominator by 1.9 to arrive at:
2 × 10^6
105 = 2^ ×^10
(^1) = 20. The correct answer is D.
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