Teaching probability and combinations has never been easier with Counting Tree. This app uses common probability tools (spinners, coins, dice, bags of marbles, and cards) as well as user defined custom events to generate counting trees that demonstrate the outcomes made possible when multiple events occur.

Users pan and zoom within large trees to focus on particular events or zoom out to demonstrate how small changes in the number of possibilities can create large numbers of outcomes.

Counting Tree assists teachers in the customization of instruction to real-time classroom discussions, the adaptation of lessons for students with special needs, and in the creation of high quality at-home activities. Trees can be emailed as PDF files to assist students at home or for insertion into worksheets, quizzes, and tests. Trees are also printable on Airport capable printers.