Are you active-duty military? If so, are you sure you have to file the SD100?
If you are an Ohio resident stationed outside of Ohio, you can exclude your military income from Ohio adjusted gross income. Therefore, no Ohio or school district tax will be calculated on your active duty pay.
If you are a nonresident of Ohio stationed in Ohio, then your military pay is not taxable to Ohio or any School District. However, any income earned other than active-duty military pay that is excluded on the return is subject to Ohio tax and the School District tax.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.