converting a number to scientific notation
in S.N., the decimal point is immediately to the right of the leftmost significant digit
the number of places that the decimal point must be moved is the size of the exponent of ten
the direction that the decimal point is moved determines the sign of the exponent
moving to the left means a positive exponent; to the right means a negative exponent
58,000,000 becomes 5.8x10^?
the decimal point moved 9 places to the left. 5.8x10^9
0.0025 becomes 2.5x10^?
the decimal point moved 3 places to the right. 2.5x10^-3
