The use of standard form can make calculations so easy that calculators are not needed. No really!
You should know that when numbers are multiplied together, it doesn't matter what order we do this. Since numbers in standard form involve powers of ten, when we have to multiply, or divide, them we can combine the powers together to make things easier:
e.g. 2×106 × 3×102
Notice that we just add the powers of ten - easy! When dividing, we subtract the second power.