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?

In your declarative next-generation non-shit programming language that currently doesn't exist outside your brain, should cardinals (and thus the entire numerical tower) be defined in terms of Church numerals?

Discuss.