Question

A scientist observed a bacterium in a microscope. It measured about 0.0000029 meter in diameter. Which of the following is closest to 0.0000029?
How many times larger is
3
×
10
6
than
3
×
10
1
?

A.
243

B.
729

C.
100,000

D.
300,000

Answer 1

0.0000029 m = 2.9 × 10^−6 m = 2.9 μm (about 3 × 10^−6 m, i.e. about 3 micrometres).

(3 × 10^6) ÷ (3 × 10^1) = 10^(6−1) = 10^5 = 100,000 — answer C.