Hello anybody out there!

I have a question. On question four of the assignment, I believe the answer is "less than a number"(I can't write the answer here), which uses the symbol, <. Unfortunately, the computer won't let me type in that symbol as an answer. My question is, did I do the problem wrong? Or, if I am right, how should I express my answer? Thank you so much!

Sincerely,

Yoyo