# Crystal Capture

This weekend I made something fun and wanted to share it in case it provides fun for anyone else.

My daughter has a board game called Unicorn Glitterluck.

It’s super cute, but not the most engrossing game. She and I especially like the purple cloud crystals, so this weekend I started brainstorming a math game I could make for us to play together. I know number combinations is an important idea she’ll be working on in 1st grade, so I thought about how to build a game around that while also incorporating the crystals.

Introducing…Crystal Capture!

Knowing that certain totals have greater probabilities of appearing than others, I created a game board that takes advantage of this. Totals like 6, 7, and 8 get rolled fairly frequently, so those spaces only get 1 crystal each. Totals like 2, 3, 11, and 12, on the other hand, have less chance of being rolled, so I only put 1 space above each of these numbers, but that space has 3 crystals.

I mocked up a game board and we did a little play testing. I quickly learned a few things:

I originally thought we would play until the board was cleared. Everything was going so well until all we had left was the one space above 12. We spent a good 15 minutes rolling and re-rolling. We just couldn’t roll a 12!! That was getting boring fast which led me to introduce a special move when you roll a double. That at least gave us something to do while we waited to finally roll a 12.

That evening I made a fancier game board in Powerpoint and we played the game again this morning:

Since clearing the board can potentially take a long time, which sucks the life out of the game, I changed the end condition. Now, if all nine of the spaces above 6, 7, and 8 are empty, the game ends. Since these numbers get rolled more frequently, the game has a much greater chance of ending without dragging on too long.

I did keep the special move when you roll doubles though. This adds a little strategic element. When you roll a double, you can replenish the crystals in any one space on the board. Will you refill a space above 6, 7, or 8 to keep the game going just a little bit longer? Or will you replenish one of the three-crystal spaces in hopes of rolling that number and claiming the crystals for yourself?

All in all, my daughter and I had a good time playing the game, and I learned a lot about where she’s at in her thinking about number combinations. Some observations:

• She is very comfortable using her fingers to find totals.
• Even though she knows each hand has 5 fingers, she’ll still count all 5 fingers one-at-a-time about 75% of the time.
• She is pretty comfortable with most of her doubles. She knows double 5 is 10, for example. She gets confused whether double 3 or double 4 is 8. We rarely rolled double 6, so I have no idea what she knows about that one.
• In the context of this game at least, she is not thinking about counting on from the larger number…yet. She doesn’t have a repertoire of strategies to help her even if she did stop and analyze the two dice. If she sees 1 and 5, she’ll put 1 finger up on one hand and 5 on the other, then she’ll count all.
• I did see hints of some combinations slowly sinking in. That’s one benefit to dice games like this. As students continue to roll the same combinations over and over, they’ll start to internalize them.

Several folks on Twitter expressed interest in the game, so I wanted to write up this post and share the materials in case anyone out there wants to play it with their own children or students.

You’ll have to scrounge up your own crystals to put in the spaces, but even if you don’t have fancy purple ones like we do, small objects like buttons, along with a little imagination, work just as well. Oh, and if you can get your hands on sparkly dice, that helps, too. My daughter loves the sparkly dice I found in a bag of dice I had lying around.

Have fun!