Scheme/DrRacket

How do I write a function that takes any integers in a list and produces the number of values in the list whose one's digit (i.e. the least significant or rightmost digit) is 1. For example,
(ones (list 82 231 1 22 1000)) => 2?

>>6
Lisp has other fold procedures too, check srfi-1. I'm curious though, what's the difference between fold, reduce, and fold-right?