Question

By the end of the year, Class A had earned 3.54 x 10^5 points for gathering cans to recycle. Class B earned 2.6 x 10^4 points and Class C earned 3.505 x 10^5 points. Which class earned the most points? By how much?

Answer 1

Class A, by 3.5 × 10³ points

Explanation:

When comparing numbers in scientific notation, the one with the largest exponent will be the largest. When two numbers have the same exponent (as here), then the one with the largest mantissa is the largest.

3.54 × 10^5 is the largest of the given numbers. It is the number of points earned by Class A.

Class C earned the second-largest number of points, 3.505 × 10^5. The difference of these two numbers is ...

... 3.540 × 10^5 - 3.505 × 10^5 = (3.540 -3.505) × 10^5

... = .035 × 10^5 = 3.5 × 10^3