Multiply the 0.00070080 by 10, 4 times, making it a 7.008. When you multiply each time by 10 it moves the decimal point to the right one time. To keep the number the same you put x10 to the 4th power next to the 7.008. This makes your answer 7.008x10 to the negative 4th power.
Hope I could help! :)