Hey Funky, Ok, I re-read the site. It says, for every 1kg of the puppy's body weight, you want to give 5% in grams (of his body weight). So, Luna is 4 lbs. That is about 2 kg. (1kg=2.2 lbs). And 5% of 2 kg is 100 grams. I believe 1 cup is about 80 gms and 1/2 cup is about 40 gms, so you want to give a little more than 1/2 cup each time you feed him. And of course, I like to add a couple of snacks here and there, only a spoonful at a time though. Like today, b/f Max's dinner, I gave him some cut up pieces of peaches I was eating.
Now, when they mature (after 1 year for Yorkies), you want to give them about 4% or the body weight, so 1/2 cup twice daily will be fine. Add a couple of snacks
I noticed that Max is always ready for food and treats. I think maybe Luna is hungry if she was even crying, but maybe Luna is just likes eating like Max

I believe many yorkies just love eating. Cheers!