Friday Favorites - Warmup Activities

This will be one of my last consistent Friday Favorites posts, as pre-planning starts next week. I will still try my best to do a weekly post about education, sewing, or food though. So stick with me and cross your fingers that I get it done!

This week, I'm listing my three favorite warm up activities. These also go by the name of bell ringers, introductory focus, etc.  Before school starts, I really want to make a bank of possible warm up ideas. That way, during the school year I can pick a type from my list quickly, instead of having to do the research during the school year. (I may post my list later on.) These will be more so math centered, because that is what I'm teaching this year.

1. Find the lie - List 3-5 problems that are solved. One of them will be solved incorrectly. The students have to figure out which one it is, figure out what the person that solved it did wrong, and they have to figure out what the correct answer is. 
2. Math journal entry - Put up a problem, and students have to solve it while writing about what they did. They have to show the teacher how they thought through the problem, by putting each and every step into words. 
3. Present a math scenario - This year, I am using this as extra credit. I will have a designated spot in my room for students to put up their examples of math in the real world. During the warm up, students can present their examples for one more extra credit point. 

What are your favorite warm up activities?