# The Red Box Challenge

Here is another hundreds chart that I created in PowerPoint.  This is the Light Switch Hundreds Chart.  Can you explain why it arrives at the final set of numbers?  Try to think outside of the “box.”  You’ll understand what I mean in just a moment…

Update:  This challenge has been solved one time now.  Congratulations to Rik Rowe’s High School Math Class in Massachusetts who have been the first to solve.  Thanks @whsrowe for challenging your class and for sending me the answer.  I am very impressed.  The challenge remains extended to all others.  Can you explain why this is true?

### 8 responses to “The Red Box Challenge”

1. Extension problem: would it still be the perfect squares if you click on every multiple and not just the first ten multiples?

1. stevewyborney@gmail.com

I was hoping someone would ask that very question! As food for thought, if you clicked on multiples of 11, I don’t think it would erase any of perfect squares, so they would still stand. However, it would “clutter” the chart with some additional numbers. So that makes me wonder what it is about 10 that is unique. The one piece that catches my attention is that I chose to use the first 10 multiples of each number. What would have happened if I chose the first 9 multiples of each number, or the first 5 multiples, or the first 12 multiples.

Nice question!

2. Dean Timmons

Absolutely love it!!! Is there a downloadable version of the lights table?

1. stevewyborney@gmail.com

Hi, Dean. I don’t have a downloadable version, but your comment has encouraged me to set one up. I think that will be my next step.

1. gaby

3. I have taken your excellent idea and put it into code that lives on the web: no downloads or plug-ins to slow it down. Hope someone finds it useful! http://www.scienceoftech.net/HundredsChart.php ( It’s a modification of the Animated Multiplication Table I shared earlier…)

4. My son and I watched the video and talked about the pattern. He immediately noticed those numbers had something to do with the multiplication table he learned/talked about in 3rd grade. I teach 1st and love math. My son is in 6th grade and loves math too. Those numbers are squares of the numbers 1-10. Twitter handle @teachjwright

1. stevewyborney@gmail.com

Great catch, Jeanne. Yes, they are all square numbers. I’ll add some more information below to explain why that is…