Convert numbers to standard form by placing decimal point where there is only one non-zero digit to the left. Then count the number of decimal places the decimal has moved from the original number, writing the number of times as an exponent of 10.
The exponent is negative if the original number is less than 1, and positive if the original number is greater than 1. For example 4,750,000 is written in standard form as 4.75 x 10 to the power of 6, while 0.000789 is written as 7.89 x 10 to the power of negative four. In these examples, there is only one non-digit zero to the left, and the number of times the decimal moves is used as an exponent.