This is a very simple activity to improve reading comprehension.
Write a phrase on the board leaving out all the vowels. Students have to fill in the missing letters to guess the phrase.
L-t's r--d th- n-wsp-p-r
Wh- -s th- m--n ch-r-ct-r -n th-s b--k?
You can also write orders and the students have to perform the action. The first one to do it correctly wins a point.
-p-n y--r b--ks
R--s- y--r l-ft h-nd