In hex that is 000000011001.(12 bits remember?)
First of all that's binary, in HEX it is Hx019
Your second - "makes more sense" guess is correct. To clarify this to you most and least important bits goes like this.
(most important)(least important) = number
By most important we mean that if something changes there, then the number is gonna change a lot.
By least important, on the other hand, we mean that if something changes then the number is gonna change little.
And that's a good way to remember it.
so if I have let's say this number:
0000 00000001 that equals 1
if I change something in the least important byte, for example:
0000 00100001 that equals 33
But if I change something in the most important byte, it will go like this:
0010 00000001 that equals 513
So if you want a small number (less than 255) you try changing the least significant byte
If you need a number greater than 255 then you change both most and least significant bytes to "build" that number.
Best Regards, Lefteris