# Can't sum numbers?

I am currently reviewing a very large (like, over 4,000 rows, 30-some columns) dataset as part of an application process. I need to sum multiple columns together into a new column, to do this, I am using the formula =SUM(AF1,AG1,AH1,AI1,AJ1) and using the little box thing to extend it to the rest of the column. I know the the sum equation works because I have a row i filled w/ ones to test it, but unfortunately, each other row in that column is resulting in a zero. I already changed all the columns to get rid of the $ signs in front of them [using =RIGHT(K1, LEN(K1)-2)] but it's still not working. I have tried to format the numbers into numbers, but I'm not sure if I'm doing it right, because it's still not working. Most of the numbers have commas in them, all of them are followed by a decimal point and two zeros. How can i fix this so can sum these columns?