Several times a week I see one of my math class at the start of snack time. Because we are a 1:1 laptop school, I can’t have my kids use their computers while they eat snack. On these days I use something for a warm-up that encourages conversation and does not require technology use from the students. Sometimes I project a picture from Which One Doesn’t Belong, sometimes I pose a question, etc. I recently added Four Strikes and You’re Out from Marilyn Burns’ blog. It’s a quick game that starts with guessing and quickly demands the use of number sense. You start with a basic frame like this:

____ ____ + ____ ____ = ____ ____ 0 1 2 3 4 5 6 7 8 9

Students guess a number. If it’s part of the equation, I write in the number. If not, I cross out the number from the list on the right. Think Hangman but with numbers. Once there are a few numbers in the equation, kids start to reason through their guesses. This sparks great conversation. I tell the kids they are playing against me – this causes the kids to work together and explain their reasoning (MP3):

*“No, don’t guess nine – it’s too big – look at the numbers in the one’s place!”*

*“It has to be five – see the zero?! *

*“Can I come up to the board to explain?”*

The kids are engaged (while noshing on delicious looking snacks) and talking about math – I call that a win!