Science Smarts: Get ready for some math magic
By PATTY ROOKS on June 12, 2021.
This week, I am venturing out a little bit. I am embracing STEM. If you do not know what STEM stands for, it is an acronym for Science, Technology, Engineering and Math. At Praxis we like to embrace STEM and show you each and every week in this article a bit about it. Unfortunately, I sometimes forget about the math … not because I do not like it, but because it can be hard to explain. But this week, I had someone show me a bit of “math magic” that I cannot wait to share. I hope I can do this magic trick justice. Let’s get started! Remember to ask an adult before doing this experiment Materials • Helper • Pen or pencil • Two sheets of blank paper Procedure • In this activity, you are going to guess the middle number in a math equation your helper assists you with. I am going to give you the answer to write down now: you are going to write down the number nine (9) in secret on a blank piece of paper. Fold this paper over so your helper cannot see it and set it aside. • Have your helper write any three digit number they want on a different piece of blank paper. • Reverse the order of the numbers and subtract them from the initial number. • Based on the answer, ask your helper if the number you guessed is the middle number or the sum of the outside (first and last number). • Check with the number you wrote in secret on the paper. • Do they match? Explanation You should have guessed it correctly as 99% of the time; the answer will be nine (9)! Let me show you the math as sometimes a visual is much more helpful. I will guess the number 439. Reverse the numbers and subtract them (always subtract the larger number from the smaller number as we do not want to deal with negatives): 934 – 439 — 495 (Answer) The middle number is nine (9). Now, also notice that if you add up the first and last digits in the answer the sum is also nine (9)! There really is not any magic here. Many schools of thought weigh in on why this works as it does, and I will leave that up to you to research! Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. NOTE our NEW address: #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403-527-5365, email: praxis@praxismh.ca. 26-25
