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Showing posts from May, 2013

Ratios and Proportions...and Goldfish!

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Fraction Krypto

Krypto is a game I learned about at a conference where Dr. Lola May presented (in like 1993, I think!). I didn't realize until recently that it was a commercial game that could be purchased :-)   I had simply used the game idea from time to time, following the rules as laid out in the book. Krypto can be played with whole numbers or fractions (and with positive and negative integers as well, I'm sure!), but for today, I'm going to talk about the use of it with fractions. The rules are simple (kind of like the "24" game): 1. Choose 5 common fractions, with denominators of halves, thirds, fourths, sixths, eighths, tenths and twelfths. 2. Students add, subtract, multiply, and/or divide the fractions to make the 5 fractions equal the target number of 1. 3. Students can receive points for meeting the target number of 1. If they do so using only 3 numbers, they get 300 pts; 4 numbers = 400 pts; all 5 numbers = 1,000 can set up the point system any way yo

"Casting Out Nines"

I was a very new teacher (in my second year, I believe), when I was lucky enough to go to a conference and hear Dr. Lola May speak. She was a great presenter, and certainly made an impression on me. I still (20 years later) have the book that was given at the conference and refer to it now and again. It was at this conference that I first learned how to use "casting out nines" to check the answers to multiplication and division problems. I had never heard of this method when I was a student, but being a new teacher, I kind of assumed it was a method well-known to other teachers.....until I talked about it during a meeting at which our Curriculum and Instruction director was present. He overheard me explaining it to another teacher; he had never heard of it, was quite surprised and interested in how it worked, and asked me to show him a few more examples. Over the years, I have taught it to some classes (and not to others...I haven't taught it yet this year, but plan t