I do them daily as part of our whole-group warm-up. People do different things, but for us it's a matter of looking at math dot cards:
A few other math ideas:
I use these as a whole group activity. I ask the students to hold up theirs if it equals more than 5 or less than 3. It's a quick activity but they have to incorporate that addition and know where the number falls on the number line.
Using real life photographs. I love this site: http://www.msnbc.msn.com/id/3842331/ MSNBC's This Week in Pictures. I use it for my oral language in reading, but also for math.
I love to do a tricky one with the shapes. How many rectangles are there? They will forget to count the tables.
How many people? How many legs? If one person left, how many people are there?
You can go on and on making those real-world connections!