[Tutor] Add all natural numbers that are multiples of 3 and 5

[Benjamin Serrato]

Hello,

I'm trying to correctly solve the first projecteuler.net problem. The
question is as so: Find the sum of all the multiples of 3 or 5 below 1000.

I wrote the following program, but the number found is incorrect. I created
a function that adds multiples of a given number to a global variable until
the multiples are greater than 1000.  The solution I get with my code is
"1224". This is incorrect, but I am having trouble understanding why my code
is wrong... it's very simple.
My code:

#!!/usr/local/bin/python3.0
#problem1.py

"""Lists the sum of all multiples of 3 and 5 less than 1000."""

# Initialize variable 'total'.
total = 0  # I wanted this to be 'None', is that wrong?

def sumTotal(multiple):
    global total  # Brings total into the local scope so it
                      # can be written to.
    n = 2
    while multiple < 1000:
        total = total + multiple
        multiple = multiple * n
        n = n + 1   # I wanted this to be += but I'm not sure
                        # that is right.

# Now I call the function with the two arguments I need, 3
# and 5.  Since total is a global variable it retains its value
# at the end of the first function call, the next call adds to
# the total value.  Thus print(total) should give me the correct
# value.

sumTotal(3)
sumTotal(5)

print(total)

-----
I think I have made a mistake with scope.  Or some other syntactic error,
because I don't see anything wrong with the code. Please make it obvious for
me.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/tutor/attachments/20090103/5b940fdc/attachment.htm>