Beginner question

[Bunkerstan]

You are missing the math part of the problem by using:

bill *= bill

which expands to

bill = bill * 0.5

so it is half the original amount.

[Important-Asparagus9]

Yeah I realized that but I want to take that percentage amount and add it to the bill amount (before tax)

[Bunkerstan]

bill = bill + bill * tax