Question

Find a whole number x in x/113 so that the ratio is a good estimate for pi

Answer 1

So the initial question is x / 113 = 3.14 (we're keeping it a smaller decimal for now)

What you should do first is multiply both sides by 113

Your answer should be x = 354.82

Round this up to x = 355. <-- This is why we only used 3.14 at the start

Now check your work:
x / 113 = ?
355 / 113 = 3.14159265358979... which essentially is pi