I can’t find my kitchen scales, how do I take 115g of flour from the bag without them?!?

Establish what weight is in the full bag. Then calculate what percentage 115 grs is of the full bag. If it is, say a third or a quarter or a fifth. Then if it is a 1/3, place 3 empty cups on the table and fill them up equally, use one and pour pack the other 2 into the bag. If it’s a quarter, use 4 cups, for a 1/5 use 5 cups.