Integer Black Jack

So, my colleagues and I are reading Principles to Action in order to improve discourse and questioning. We also use problem solving tasks in our class but not as frequently as I would like. To that end, I am planning to attempt a lesson plan with a hook and plenty of chances for discourse. I am planning this lesson for sometime in September after integer addition has been introduced with number lines and chips.

Integer Black Jack

I also got the idea from these two sites:

I really like this idea for many reasons. I think students always need practice especially at the beginning of adding integers and I think this will really solidify the idea of absolute value and why you use this.

Materials needed: 8-9 decks of card (one for each table of 4), white boards or chart paper.


Do-Now is from the would you rather site:

WYR Blackjack

Hit or Stay?

Students will have some private think time to come up with arguments and write them down in their journal, with a brief intro of the rules of blackjack:

1) Jacks, Queens and Kings are worth 10.  Aces are worth 1 or 11.

2) You can ask the dealer to “Hit” you for a total of 4 cards.

3) Object of the game is to get 21 or as close to 21 without going over and beat the dealer.

I will then have students share in pairs what they think (turn and talk) and then have at least 5-6 students share their reasoning.

Then I will introduce the idea of Absolute Value Blackjack.

Each table of 4 will play with the winner of each round getting to be the dealer of the next round. (Each player has the incentive to check the math of the other players to see if they win)

Same rules as blackjack except for two important differences:

A) Black cards are positive. Red cards are negative and you need to add together to get your total. So for example Red 4 + Black 9 would be +5. Red 4 + Red 9 would be -13.

B) The winner is the person with the highest ABSOLUTE VALUE without going over 21.

Example: If someone has Red Queen and Red Ace, (so -20) and another person has Black King, Black 2 and Black 7 (+19) the person with the Red wins as the absolute value of 20 is greater than the absolute value of 19.

One of my goals for the year is to get students to have more discourse and for me talk less. I was reading about using mistakes in presenting purposely here, and thought this would be a good lesson to test it out. The main idea is that students put at least one deliberate mistake so that when they are presenting, everyone needs to look for a mistake. I like this in theory as it takes pressure off of a presentation for making a mistake and if they make an unintentional mistake, there is less possible embarrassment for the student as they could have “meant” to do that.

After playing for awhile, pass out white-boards, one per group and have them draw their next hand on the white board using black and red expo markers. Tell students you would like to see at least one deliberate mistake and that they have 5 minutes to do this.

As I haven’t done this yet, will have to see how it plays out but hopefully students will show why one person was the winner in the hand and have a clearer idea of what absolute value is as well as thinking out adding integers and what circumstances make a positive/negative.

Differentiation: Make sure to have chips and number lines available for those students who need to use them in adding their cards together. Variation of game could be winner is the one “closest to zero” instead of 21. Have students think about how that changes the game.

HW: In journal writing, write two noticings and two wonderings about the absolute value blackjack game.

Example of a wondering: How would the game change if it was a different number but 21 that you had to get closest to?

Example of a noticing: I notice that when you add a black card (+ number) and another black card (+ number), you get a higher black card. (+ number.)

Hope to write back with how it went once I do it.





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