The Birthday Problem

How many people do you need in a room before two likely share the same birthday? Scholars consider this puzzle by analyzing a set of data. They ponder how to divide the data and determine the proper size of a group for this event to...

In this ratios activity, students complete 3 ratios for each word problem containing 2 digit numbers. Students complete 9 ratios total.

What is the probability that two people out of thirty have the same birthday? Sal tackles this problem with his characteristic skill and casual attitude. Students will find his process easy to follow - and the solution to the problem...

Apply what you learned in videos one and two on the substitution method with this application problem. Sal uses the substitution method to solve a system of equations.

Happy birthday to you — and to you! A festive video on probability examines the likelihood of two people in a group sharing a birthday, based on the size of the group. 

Use dependency to find a birthday. Learners use an interactive to keep track of excluded potential dates of a birthday using information provided to two people about a third's birthday. Scholars then use the dependency between the dates...

In this birthday problem worksheet, students solve 1 probability word problem.  Students determine the number of people needed to have a 50% probability that two people will have the same birthday.

Twelfth graders determine the probability of two people in their class sharing the same birthday.  In this determining the probability of two people in their class sharing the same birthday problem lesson, 12th graders use Mathematica to...

Mindful middle-schoolers read and solve a number of word problems. Learners copy and discuss what they believe their strategies are in solving each problem. They also write their findings and share with the rest of the class.

Young scholars identify the probability of an event occurring. Learners explore the complement of an event in finding why an event will not happen. They also explore basics of probability within algebra.