11-06 Handshakes Visualization

We've been thinking about algorithms and data and have seen different kinds of visualizations. Now it is time to make our own.

For this journal entry consider the following question:

Assume there are 20 people in the room, including you. Everyone must shake hands with everyone else in the room.

1. How many handshakes will there be when there are 20 people in the room? Assume that if person A shakes hands with person B then that counts as a single handshake and you don't separately have to count person B shaking hands with person A.
2. If there are n people in the room, how many handshakes will there be?

Consider how you represent this problem and make choices so that the representation of your solution would make sense to a younger sibling or niece or nephew, at the level of a 3rd grade student (~10 year-old) would get it. Think of how we have represented problems in the past: physical modelling, explaining with words, using pictures.

Remember the video we saw on "How to Eat a Bicycle" (…one small piece at a time). I suggest you think about how you would solve and represent this problem if there were only 2 other people in the room. Then 3 people, and so on.

Use the 11-6 Handshakes Visualization form to post your essay which will be graded as follows:

1. (2 points) The strategy is demonstrated visually.
2. (2 points) The strategy is developed in an easy to understand step-by-step manner, suitable for a 10 year-old 3rd grade student to understand.
3. (1 point) The accompanying text is clear and accurately explains the process.