Students learn to convert a number from standard notation to scientific notation by first writing a decimal point in the number so that there is only one digit to the left of the decimal point. For example, to write 642,000 in scientific notation, first write the number so that there is only one digit to the left of the decimal point, which in this case is 6.42000. Next, count the number of places that the decimal point must be moved to get back to the original number, which in this case is 5 places. This number will be the exponent on the power of 10. So 642,000 can be written in scientific notation as 6.42 x 10^5. Note that the exponent is positive, because the original number is a whole number. If the original number were a decimal, the exponent would be negative. For example, 0.059 written in standard form is 5.9 x 10^(-2).