the mass of a certain grain of rice is about 3 x 10^-2 grams. The mass of a certain grain of salt is about 6 x 10^-5 grams.

1) which has a greater mass?
2) how many times greater is the mass of the larger grain than the smaller grain?

4 answers

well, 10^-2 is 1000 times as big as 10^-5
That is, 10^-2 = 10^-5 * 10^3
2) how many times greater would then be 40 times?
not even close...

(3 x 10^-2)/(6 x 10^-5) = 3/6 x 10^3 = 500

How ever did you get 40?
sorry I'm working on another problems as well, yes 500

3/6 x 10^-2-(-5)
.5 x 10^3
500