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14 votes
The estimated populations of the three countries with the greatest populations in 2015 are shown.

China: 1.36 times 10 Superscript 9
India: 1.25 times 10 Superscript 9
United States: 3.2 times 10 Superscript 8

How many more people lived in China than in the United States in 2015, according to these estimates?
1.04 times 10 Superscript 8
1.84 times 10 Superscript 8
1.04 times 10 Superscript 9
1.84 times 10 Superscript 9

User RonLugge
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2 Answers

26 votes
26 votes

Answer:

c

Explanation:

User Jakebman
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2.9k points
25 votes
25 votes

9514 1404 393

Answer:

1.04×10⁹

Explanation:

Your calculator can figure this for you. You may have to set the display to show the result in scientific notation.

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1.36×10⁹ -3.2×10⁸ = (1.36 -0.32)×10⁹ = 1.04×10⁹

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Additional comment

The exponent of 10 in a number written in scientific notation relates to place value. In the number 100, for example, the digit 1 is in the 3rd place to the left of the decimal point, or the 2nd place to the left of the units digit.

The units digit has a place value of 1 = 10⁰. Digits in the hundreds place, as in 100, have a place value of 10², where the 2 corresponds to the 2nd place to the left of the units digit. Effectively, the number places correspond to exponents of 0, 1, 2, 3, ... as you move to the left from the decimal point.

A number like 3×10⁸ will have the digit 3 in the place that is 8th to the left of the units digit (9th to the left of the decimal point). Effectively, the 3 is followed by 8 zeros. The decimal point in 3.2×10⁸ means the digit 2 is in the number place immediately to the right of the one with place value 10⁸. The exponent of 8 in 10⁸ effectively tells you that moving the decimal point 8 places to the right will put the number in standard form.

1.0×10⁸ = 100,000,000.

User Dfreeman
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2.8k points