   SEARCH HOME Math Central Quandaries & Queries  Question from ASTRID, a student: how can you solve the following pr0blem... the mean distance between the sun & pluto is about 3,700,000,000 miles. write this distance in scientific notation? Astrid,

There are instructions for writing a number in Scientific notation in the answer Sara gave to a previous question. Following her instructions the first two non-zero digits in 3,700,000,000 are 3 and 7 so put the decimal between them

3.7

To move the decimal from being between the 3 and 7 to the position of the decimal in 3,700,000,000. you need to move it 9 places to the right, in other words you have to multiply by 1,000,000,000 which is 109. Thus

3,700,000,000 = 3.7 × 109.

For your second problem which is to evaluate (2.5 x 10^5) (1.56 x 10^-3) write

(2.5 x 105) (1.56 x 10-3)
= (2.5 x 105) × (1.56 x 10-3)
= 2.5 × 1.56 × 105 × 10-3

Can you complete the problem now?

Penny     Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.