why is the math in my code not working properly?

Question

I just started coding and tried to make a type of a calculator that i could come up with by myself. Today I realized that for example when calculating 2.3 - 3 the result is -0.7000000000000002 so I am not looking for advice in how to make my code better tbh but to learn just why it is not making the calculations correctly. I know this code is bad but here it is:

num_1 = input("Enter a number: ")
math_problem_type = input("what kind of a math problem? Enter +, -, * or / : ")
num_2 = input("Enter another number: ")


def addition(num_1, num_2):
    return float(num_1) + float(num_2)


def difference(num_1, num_2):
    return float(num_1) - float(num_2)


def product(num_1, num_2):
    return float(num_1) * float(num_2)


def quotient(num_1, num_2):
    return float(num_1) / float(num_2)


if math_problem_type == "+":
    print(addition(num_1, num_2))
elif math_problem_type == "-":
    print(difference(num_1, num_2))
elif math_problem_type == "*":
    print(product(num_1, num_2))
elif math_problem_type == "/":
    print(quotient(num_1, num_2))
else:
    print("you done fucked up bruv")