I have students work in small groups. They each get a copy of the instruction manual and the data notebook. Students also get a coin, a six-sided die, and a 20-sided die. Since I am a gamer, the d20 made sense to me. I was also very happy to have an excuse to buy a bunch of dice at my local game store (I spent about $15 for 30 dice). However, the activity can easily be modified to use a coin and d6 only.
Below you can find pdfs of the handouts. The instruction manual will walk you through the whole activity, and the data sheet is what students use to record their findings. If you had seen an earlier version of this activity, the below files contain edits that greatly streamline the process.
For more info, I published this activity in the American Biology Teacher:
"Modeling Genetic Complexity in the Classroom"
Julie J. Lesnik
The American Biology Teacher, Vol. 80 No. 2, February 2018; (pp. 140-142) DOI: 10.1525/abt.2018.80.2.140
Feel free to contact me here if you would like a pdf of the paper.