To write decimals in standard form, move the decimal point to the right until it is at the right of the first nonzero digit. Then, multiply the number by 10 to the power of the negative of the number of spaces the decimal point was moved.
For example, the decimal 0.0000005467 can be expressed in standard form as 5.467 * 10^-7. This is because in order for the decimal to be to the right of the first nonzero digit, it has to be moved seven places to the right. After moving the decimal seven places to the right, the resulting number is 5.467. Then, this number is multiplied by 10^-7, because when moving the decimal to the right, one must multiply by 10 to the power of the negative of the number of places the decimal point moved.
Another simple example is the decimal 0.01. It can be expressed as 1 * 10^-2, because the decimal has to move two places to the right in order to be to the right of the first nonzero digit.