As a mathematics teacher, I found myself logging assignments in the gradebook by title, but forgetting what numbers I did in fact assign. That's when I turned to a spreadsheet to keep an ongoing record. When a student asks "What did I miss?" I can turn to this and tell them exactly. As you can see, I have divided mine particularly by subject area, as well as marking period tabs (at the bottom).
Hope you find this as useful as I do!