With Match stick...

I hold up the sky; I hold many pounds. Just so you know, I can never fall on the *ground*. I am made of the world; without me you'll die. The ones who survive are the ones that can fly. What am I?

The equation shown below is not correct:

26 - 63 = 1

Can you make the equation correct by moving just one digit?

5 + 5 + 5 = 550

Can you make the equation correct by placing just one stroke?

In this picture you can see 6 coins in the shape of a cross. Moving just ONE coin, can you form 2 lines, each with 4 coins?