Ease of multiplying or dividing, especially when estimating. Just add or subtract the exponent and you know about how large the answer is. example, 4.123 x 10

Less chance of errors, there's no need to deal with lots of leading zeros in numbers less than one. Example, in the number 0.00000004, it is easy to miss a zero, but 4 x 10

^{-1}x 2.092 x 10^{3}, we know right away the answer is about 8 x 10^{2}. Sometimes that's close enough.Less chance of errors, there's no need to deal with lots of leading zeros in numbers less than one. Example, in the number 0.00000004, it is easy to miss a zero, but 4 x 10

^{-8}makes it easy.