Good luck!
Puzzle #1
This is one someone told me and it took me forever to work out! A man rides into a town on Thursday. He stays for two nights and comes out on Thursday. How is this possible?

His horse is called Thursday of course.

Puzzle #2
There is a house which has all four walls facing South.  Where is the house?  A bear walks past, what color is it?

The answer to this is simple.  The house is in the North Pole and the bear is white!

Puzzle #3
You might want to draw this one on a piece of paper, or you might not!  Add one line to IO IO IO to make 9:50.

IO TO IO (Ten to ten=9:50!)

Puzzle #4
IIIIII.  These are six matchsticks.  Add five to make nine.

NINE = IIIIII + \ \ - - - (five matchsticks)