If a dress costs $27.00 when it is on sale for 10% off, what is its original cost?

30

Step-by-step explanation:

you could also say this question like this:

"if 90% of the number is 27, what is the number?"

So you do 27 / 90%

27 /.9

27 / 90 * 100

30

I may not have answered this super throughly sorry ...