

def add(first_term, second_term):
    return first_term + second_term


def subtract(first_term, second_term):
    return first_term - second_term


def multiply(first_term, second_term):
    return first_term * second_term


def divide(first_term, second_term):
    return first_term / second_term
# the first step in testing is to lint the code which checks for possible
# syntactical errors

# the second step is unit testing
# unit testing is designed to check a single function or unit of code

# another standard that goes hand in hand with testing is called code
# coverage. coverage is the percentage of the source code that is
# covered by tests
