Explain how to do 63 is 90% of what number

To do this, you must first turn 90 percent into a decimal, by dividing it by 100.  The decimal should be .90 .  

Now, you must divide 63 by .90 which will give you the number that 63 is 90% of.  The answer should be 70.

To help you understand this, think about finding 90% of 70.  To do this you could do 70 times .90 (decimal form of 90%) which would give you 63 as your answer.  This is because 70 is being multiplied not by 1 (its fullself), but by .90 which will give you 90% of 70.

Finally, the opposite of multiplying is dividing so to find 90% of 63 you do the opposite.  You divide instead of multiply since you are trying to find what 63 is 90% of.

Remember to study and work on finding the lesser number that represents the percentages of the full numbers and turning them into values, and vice versa, like in this question.  So for example, finding what number is 10% of 90.  You would have to multiply 90 by .10  .  The answer would be 9.

To recap, the answer you should come up with for your question is 70.

I hope this helps!