Change the decimals to the form whole number ×10a Where the power (a) is the number of times you have to move the decimal point in order to get a whole number When you move to the right, the power is negative and when you move to the left, the power is positive 64.5=645×10−1 (The decimal point has to be moved once (1) to the right) 0.015=15×10−3 (The decimal point has to be moved three (3) times to the right) From the law of indices am∕an=am−n =43×10−1−(−3)=43×10−1+3=43×102 Now change the result to standard form. The standard form rule says the decimal point must be after the first non-zero digit. 43=43.0 so we have to move to the left once and since to the left, the power is positive (1) 43=4.3×101 From law of indices, am×an=am+n 43×102=4.3×101×102=4.3×101+2=4.3×103 in standard form