If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

Can You Find the Missing Zero? A Number Puzzle that Will Trick Your Eyes

What breaks yet never falls, and what falls yet never breaks?

Fate has decided that you will only be pleased to meet me when you need me

Maybe that is why, when I am working, I start working

However annoying I may be to the regulars, the little ones are always inspired

I will always be waiting if you try to reach me

How many of you can guess my name, let me see

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

What demands an answer, but asks no questions

How many letters are in the alphabet?

Riddle me this, Riddle me that,
What am I? I am made of wood, but you can't see me down?

The more of this there is, the less you see. What is it?