Tag Archives: probability

WYCDWT: Deal or No Deal

Another quick post, here’s another project I’ve used in the classroom… just today actually.

We’re studying Expected Values (Probability Distributions) and I found two powerful videos from the gameshow, “Deal or No Deal” where the issue of E(X) arises quite naturally. tbh, any video of Deal or No Deal implicitly deals with Expected Values!






Hint: Use Probability Theory!

How much is this worth?







The videos can be found here: (Updated Dec. 16th)

The first video is of a contestent who has a $200,000 case left, and the $1,000,000 case left. The banker offers her $561,000 to stop playing the game. There is tons of drama, and it’s impossible not to get invested into the outcome of her decision, (Spoiler Alert: she declines the offer, and ends up with the million dollars, for a nice heart-warming ending.)

My setup: I would play the video up until Howie asks the natural hook, “So, Deal or No Deal?” and then pause the video. After the students stop groaning, get them to put themselves in the contestant’s situation and decide if they would take the deal or not (this isn’t hard :P). Have them form groups and then debate their decisions. Teasing out some math inherent in this situation is a plus, but really you just want them to invest in the problem. I used this as a nice introduction to expected values, a topic most people are unfamiliar with unless they’ve studied finite math before (or are professional gamblers!). After your students debate, play the rest of the video and ask whether it was a good decision. This segues naturally into the topic of expected values.

The second video is of a contestent who has a $0.01 case left, and the $10,000 case left. The banker offers her $5,500. This video acts as a nice consolidation at the end of the class to drive expected values home. You can ask similar questions, if she should take the deal or not. (Spoiler Alert: She ends up balking the deal and winning a penny.)

The beautiful part about these two videos is that the math works out. When the expected value is more than the offer, the contestent goes for it and wins the million. When the expected value is less than the offer, the contestent goes for it and wins a penny. It’s prudent here to talk about taking a $361,000 chance at coin flip odds. This is a life-changing amount of money, and I definitely would have taken the deal, even though I understand that the value is lower than my expected one… and I explained and justified this hypothetical decision to my students!

Just my thoughts, use as you wish!

On that note, how would you use this in your classroom?


Other notes:

1. Expected values resolve the question in my previous post, “Should Derren Brown be happy it took ~9 hours?”. Proof is again left to the reader, but the quick answer is probably not. 😛

2. Apparently I’ve won the UOIT Faculty of Education Tech Award! I didn’t know it existed, but I’m ecstatic to be the recipient! The cash prize of $500 is nice too. 😉

3. On that cash note, I’m almost done my B.Ed and ready to be certified come the end of April. I’m happy to report that I have two job interviews this Thursday afternoon. They’re both for Science and/or Math positions, and I’d be over-the-moon if I got either one. Wish me luck!


Posted by on April 5, 2011 in probability, wcydwt


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WCYDWT: Ten Heads in a Row (Hello World!)

I’ll have time to post my pedagogy and teaching philosophy later. I’ll also clean up the look of this site, pardon the dust.

I just signed up to share a project I made for a probability lesson (independent events), that could be useful for other teachers!

It’s famous UK magician Derren Brown flipping a coin and getting it to turn up heads, ten times in a row. The explanation is included: he was flipping coins for the better part of a day, until he finally got a string of ten heads together.

My Setup: Play the trick, then ask for explanations. Play the explanation video (with beeps) and get the students to try and solve for the amount of time and/or probability of this happening. If the students need to know how long a flip takes, you can play the original trick video edited with a timer. After groups have come up with solutions and explained their process, watch the full un-beeped video for the answers.

from Derren Brown, The System [2008]

The project files can be found here:

(N.B. you may want to tell your students to make the simplifying assumption that there’s an average of 2.5 flips per trial. If you want to get more complicated you can get them to do the expected value calculation for 1 flip trials, 2 flip trials, 3 flip trials, etc… and reach the expectation of 2.5 flips per trial themselves)

Should Derren Brown be happy it took ~9 hours?

Use freely!

…oh, and hello and welcome to my teaching blog. My name is Mr. Chow. 🙂

Full Disclaimer: I do not own the rights to these videos. My intention here is not to break copyright law, but instead to teach students how to think critically and learn a bit of probability. If you own this video and take issue with this, please let me know and I will remove it. Also, I am heavily influenced by Dan Meyer, David Wees, Shawn Bullock, Steven Hurley, etc… I admit openly to taking their ideas and running with them!

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Posted by on March 27, 2011 in probability, wcydwt


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