Great warm-up activity!

Teacher needs to tailor the level of difficulty to the grade/ability level of the class.

For a class of 5th graders I might say,

“Start with 5. Double it. Add 7, Subtract 9. Times 3. Divided by 6. Times 4. Raise your hand when you know the answer.”

Over the course of the year I increase the speed and the complexity, sometimes including fractions or factorials.

For primary grades I use only addition and subtraction.

from:

http://washmath.org/files/GamesAndActivities.pdf