Astronomers measure large distances in light-years. One light-year is the distance that light can travel in one year, or approxi
mately 5,880,000,000,000 miles. Suppose a star is 13.4 light-years from Earth. In scientific notation, how many miles away is it? 7.8792 x 1013 miles 1.34 x 1012 miles 5.88 x 1012 miles 5.88 x 1013 miles
After cross multiplying (1 by x and 5800...by 13.4), we have x=7.8792*10^13
Also, the answer before setting it in scientific notation was 78.792 trillion and we moved the decimal 13 times to get to 7, which is between 1 and 10.