Have you played the Factor Game? This is a great lesson - lots of fun for the students, while reinforcing the concept of factors! If you haven't played the Factor Game before, here's how it works:
|Click to download|
Player 1 chooses a number, and marks it (they might circle it square it, triangle it, color it etc). Player 2 then marks all of the remaining factors of Player 1's choice.
Player 1 receives points equal to the number they chose, and Player 2 gets points equal to all of the remaining factors of that number.
Next, Player 2 chooses a number (and gets those points), and Player 1 identifies all of the factors of that number, receiving those points.
Play continues this way until all possible numbers have been used.
*Special rule - players may not choose a number that has no factors available for the other player. If they do, they lose their turn, receiving no points.
|Student turn - choosing 30|
|My turn - choosing 27|
For my first turn, my choice would be 27, giving them only 9, since 1 and 3 are already gone.
After their experience with 30 and its factors, they start thinking a bit more. They will often consider 25 or 23, but I remind them that they must leave a factor for me, and 1 and 5 are already taken. For the sake of showing further steps, let's pretend that they choose 21. That leaves 7 for me.
|Student turn - choosing 21|
The game continues, alternating turns, until all possible numbers are used, as shown in the "finished game" picture.
The second time we play as a group, I might choose 27 or 25 as my first number (I don't want to choose the best "move," because I want them to discover it themselves)
We continue to play the second game, and they get a better idea of what makes a good choice.
After our games as a class, I have the students work in partners, and they normally get one or two games played before we stop to discuss at the end of the period. We always talk about what the best and worst first choices are, and bring the idea of prime and composite into the discussion.
I have been playing this game with students for at least 15 years (I think), and every set of students has loved it! I found the game when I was involved with Mathline, so long ago. If you'd like to see the original lesson plan, with extension ideas, click here.
Have you played the Factor Game?
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