Answer:
I know a word of letters three, add two and less there will be.
I'm the source of all emotion, but I'm caged in a white prison.
Round and round I go never stopping in a continuous flow. I hang out with numbers each and every day and nothing ever gets on my way. What am I?
A person's greatest asset.
What can you never get rid of when you lose it?
What never gets any wetter no matter how hard it rains?