Again, opinions vary on this. Interested in what the experts here prefer. I've Googled this topic and have come up with conflicting answers/preferences. (1) In fewer / less than 100 words, explain why you want the job. (2) Explain your strengths and weaknesses in 50 words or fewer / less. (3) Fewer / Less than 10% of Americans will be affected. (4) If 'Americans' were omitted, would it be: Fewer / Less than 10% will be affected. (5) The sign at the checkout line read "20 Items or Less / Fewer." (6) My grandfather's bakery may produce 10 percent fewer cookies and in each cookie uses 2 percent less sugar. Thanks.
My rule is that if it's a countable thing being described, it's 'fewer'. If it's an amount, it's 'less'. 1. Fewer 2. Fewer 3. Fewer 4. Depends. You'd need to describe the '10% of what'. 5. Fewer 6. Fewer / Less There can be some stickier situations that seem to be able to go both ways: If I have nine one-dollar bills in my wallet, I could say I have fewer than ten dollars (number of bills), but also say I have less than ten dollars (amount of money). Context is king when that happens.
Interesting question. I will definitely await more answers to this one to see where we end up, as it's not something I've really thought of before. My immediate thought would be to use "less" in all those cases (except the first part of no. 6), but when I really consider the meanings of the two words I must say that I fully agree with @stevesh.
