Thomas correctly spell 18 out of 20 words on his last spelling quiz. what decimal represent the portion of the rights that thomas spelled correctly

The answer is 0.90

I used a rather ghetto way to answer this question.

first, I multiplied 20 by 5 to get it to 100 then I multiplied 18 by the same number (5) and got 90. That makes 90 out of 100 which is 0.90

Cbecause they are equal so that means it is the same on both sides? ! hope this