Words at Play : Top 10 Commonly Confused Words, Vol. 1
Question:
Does the average American family have less than two kids or fewer than two kids?
Answer:
fewer
How to Remember It:
Fewer refers to things that can be counted (fewer kids, fewer chairs). Less usually
refers to quantities of things that can't be counted (less coffee, less agitation).
However, under certain circumstances less, not fewer, is more commonly used with countable things. For example: Less
than twenty miles, less than five dollars, and 1500 words or less, are considered standard.
As for the express lane at the supermarket, "ten items or fewer" follows the general rule, but "ten items or less" is also widely accepted and more often used.