TypeError: can only concatenate tuple (not “int”) in Python

Your checkAnswer() function returns a tuple:

def checkAnswer(number1, number2, answer, right):
    if answer == number1+number2:
        print 'Right'
        right = right + 1
    else:
        print 'Wrong'

    return right, answer

Here return right, answer returns a tuple of two values. Note that it’s the comma that makes that expression a tuple; parenthesis are optional in most contexts.

You assign this return value to right:

right = checkAnswer(number1, number2, answer, right)

making right a tuple here.

Then when you try to add 1 to it again, the error occurs. You don’t change answer within the function, so there is no point in returning the value here; remove it from the return statement:

def checkAnswer(number1, number2, answer, right):
    if answer == number1+number2:
        print 'Right'
        right = right + 1
    else:
        print 'Wrong'

    return right