We want to match the given decimal number with its closest approximation written as the product of a single digit and a power of 10.
Given Decimal
0.000618 [0.8em]
Approximations
A. 8* 10^8 B. 6* 10^(- 4) C. 7* 10^(- 4) D. 7* 10^9
Let's start by rounding the given number to the nearest 0.000 1. Since the digit in the hundred thousandths place is less than or equal to 5, we will not modify the digit in the ten thousandths place.
0.000 6 18 ≈ 0.000 6
Finally, we will rewrite the approximations.
Choice
Approximation
Number
A.
8* 10^8
800 000 000
B.
6* 10^(- 4)
0.0006
C.
7* 10^(- 4)
0.0007
D.
7* 10^9
7 000 000 000
We can see that the closest approximation to the decimal number is choice B.
Alternative Solution
Rewriting the number
We are given a number and want to match it to its closest approximation.
0.000618
Let's use the approximation we found in the main solution and rewrite it.
0.000 6 18 ≈ 0.000 6
We will write it as the product of a single digit and a power of 10. Let's start by factoring out 6!
