I'm making this calculator using python 3, and this is what I have so far:

print("Welcome to Calculator!")class Calculator:def addition(self,x,y):added = x + yreturn addeddef subtraction(self,x,y):subtracted = x - yreturn subtracteddef multiplication(self,x,y):multiplied = x * yreturn multiplieddef division(self,x,y):divided = x / yreturn dividedcalculator = Calculator()print("1 \tAddition")
print("2 \tSubtraction")
print("3 \tMultiplication")
print("4 \tDivision")
operations = int(input("What operation would you like to use?:  "))x = int(input("How many numbers would you like to use?:  "))if operations == 1:a = 0sum = 0while a < x:number = int(input("Please enter number here:  "))a += 1sum = calculator.addition(number,sum)print("The answer is", sum)
if operations == 2:s = 0diff = 0while s < x:number = int(input("Please enter number here:  "))s += 1diff = calculator.subtraction(number,diff)print("The answer is", diff)
if operations == 3:m = 0prod = 1while m < x:number = int(input("Please enter number here:  "))m += 1prod = calculator.multiplication(number, prod)print("The answer is", prod)
if operations == 4:d = 0quo = 1while d < x:number = int(input("Please enter number here:  "))d += 1quo = calculator.division(number, quo)print("The answer is", quo)

Addition and multiplication works just fine, subtraction and division are the problems here. One example for subtraction is if I tried using two numbers, 9 and 3, I would get -6... That is definitely incorrect. As for division, if I tried dividing two numbers, 10 and 2, I would get 0.2, which is also wrong. For division I've tried switching number and quo, and with the same problem (10 / 2), I would get 0.05... Also, I don't want to use any of the built-in functions for python, so just help me fix these errors the easiest way possible.

Your algorithm is wrong for subtraction and division. Let's look at subtraction:

s = 0
diff = 0
while s < x:number = int(input("Please enter number here:  "))s += 1diff = calculator.subtraction(number,diff)

Step through this in your head. If you're operating on two numbers (9 and 3), you will get diff = 9 - 0 = 9 on the first iteration and diff = 3 - 9 = (-6) on the next. That won't work.

Subtraction is addition if all the terms (but the first) are negated. If you think about it like that it's fairly simple:

terms = []
for _ in range(x):  # this is a more idiomatic way to iterate `x` timesnumber = int(input("Please enter number here: "))terms.append(number)
head, tail = terms[0], terms[1:]
result = head
for term in tail:result -= tail
return result

You can certainly condense this further

terms = [int(input("Please enter number here: ")) for _ in range(x)]
terms[1:] = [x * (-1) for x in terms[1:]]
return sum(terms)

Similarly with division, step through in your head:

d = 0
quo = 1
while d < x:number = int(input("Please enter number here:  "))d += 1quo = calculator.division(number, quo)
print("The answer is", quo)

With 10 and 2, you get first quo = 10 / 1 = 10 then quo = 2 / 10 = 0.2. Like we can generalize subtraction to be tail-negated addition, we can generalize division to be tail-inverted multiplication.

24 / 2 / 3 / 4 == 24 * (1/2) * (1/3) * (1/4)

And we can write the algorithm similarly.

terms = [int(input("Please enter number here: ")) for _ in range(x)]
head, tail = terms[0], terms[1:]
result = head
for term in tail:result /= term

Note that all of these can also be written with functools.reduce and one of the operator functions

terms = [int(input("Number please! ")) for _ in range(int(input("How many numbers? ")))]
sum_ = functools.reduce(operator.add, terms)
diff = functools.reduce(operator.sub, terms)
prod = functools.reduce(operator.mul, terms)
diff = functools.reduce(operator.truediv, terms)