Thread: question about the use of есть in 2 different sentences

why does example 1 below use the russian word 'есть' while the bottom example does not? Both examples are asking if someone HAS something, so why is есть only necessary in one of the examples?

EXAMPLE 1
Do you have 16 dollars?
у вас есть шестнадцать долларов?
(my attempt at a literal translation: At you exists 16 dollars?)

VS

EXAMPLE 2
How many dollars do you have?
сколько у вас долларов?
(my attempt at a literal translation: How much at you dollars?)

...And here we come to the wonderful subject of sentence stress and ellipsis in Russian.
First of all, since word order in Russian sentence is free, it is very important to place sentence stress correctly.
1. "У вас (есть) 16 долларов?" means "Is that you who has 16 dollars?" (I know someone does, but is that you or another person?)
2) "У вас есть 16 долларов?" simply means "Do you have this sum?" (The fact of possession is in question)
3) "У вас (есть) 16 долларов?" means "I know you have some dollars, but how many? Exactly 16, or a different number?"
4) "У вас (есть) 16 долларов?" Means "These 16 funny colored pieces of paper, are they dollars, or pesos, or perhaps rubles?" (I know you have 16 monetary units of some kind, but are they dollars?)

In most of the above questions "есть" can be omitted, except in (2) where it is stressed.

In "Cколько у вас долларов?" the logical stress is obviously on "сколько", so "есть" can be safely omitted. It does not have to be omitted, so you can also ask "Сколько у вас есть долларов?" and it won't be a terrible mistake — it is just that this word is not needed in this question because it is clearly implied.

To recap: (a) in Russian, some words can be omitted in so-called elliptical constructions.
(b) those words that carry sentence stress or logical stress normally cannot be omitted.

Thank you. That makes a lot of sense and wasn't as hard as I feared!