Order of operations.
In this case,
meal = 44.50 + 44.50 * 0.0675
meal = 44.50 + 3.00375
meal = 47.50375
I'm not familiar with Python but more likely than not it follows standard mathematical order of operations:
Parentheses, Exponent, Multiplication, Division, Addition, Subtraction
in that order.
A common way to help remember this is:
Please Excuse My Dear Aunt Sally