Because you are a volunteer and not a paid educator who works at least 900 hours a year, you cannot use the above-the-line deduction of up to $250 from gross income (allowed even if you don’t itemize, assuming this break is extended for 2015). However, if you donate the supplies to the school and do not restrict their use, you can take a charitable contribution deduction for your out-of-pocket costs. To do this, you must (1) itemize your deductions, and (2) have obtained the required substantiation for these costs (including an acknowledgment from the school if the cost is $250 or more).
A husband and wife who are required to live apart from each other by the terms of a decree of separate maintenance. Payments under the decree are deductible by the payor and taxable to the payee as alimony.