Well,
For example
2.34 * 10^6 will be....
2,340,000
It is because if you have the positive powers, you move your decimal to the right. In this case the power is 6 so you move your decimal to the right 6 times.
Here's another example
1.23 X 10^-2
The answer will be 0.0123 because you move your decimal two the left two times. The power is negative 2 so you move it to the left.
Final tips: If you have positive power, move it to the right and if you have negative power, move it to the left.
If you would to solve 60% of 85 is what number, you can calculate this using the following steps:
60% of 85 is x
60% * 85 = x
x = 60% * 85 = 60/100 * 85 = 51
Result: 60% of 85 is 51.
When you get to the point where the width is larger than the length, you can stop because you have exhausted all the possibilities. The greatest area will be the rectangle that is closer in to a square than any of the others.