Retirement tax questions

Thanks. I have another question regarding which section of TurboTax relates to Line 23 on Form 1040. In the past I've been able to deduct up to $250 for items for my classroom. I was confused as to which section that would be under so I haven't put that in. It seemed that the questions were geared for a home business office with no question directly related to teachers for Line 23. Any suggestions?