The side of my Ivermectin tube plunger has dose marks for every 250 lb. so each notch is for 50 lbs. I can’t see a % of a solid white tube but the plunger notches are quite clear. I have 3 different makers of paste and all are the same.
That’s how mine work. I dial up a 250 pound dose, squirt it in a syringe, and take half. The link I posted has a video that shows how to accurately measure small doses too.