This is why the English system of measurement is so inferior. Throw out those teaspoons, tablespoons, cups, pints, quarts and buy some metric measuring vessels.
Suddenly mixing two-stroke fuel becomes a kindergarten math problem.
Buy a 1 liter graduated plastic beaker and a 20 milliliter plastic syringe. When done mixing fuel, store both tools in a 3.79 liter plastic Ziploc bag to keep them clean for next time.