Friday, October 16, 2009

Percents, Ken Ken's, and Graphing Away: Math Potpourri!

Another week down.  The theme of this week was powering through.  There is never enough time so we just did the full court press.

Problem Solving.  Check
Graphing.  Check
Ten Percent of any number.  Check.
Customary units of measure in ounces and gallons.  Check.
Couple of quizzes.  Check.
Metric linear measurement. Check

Looking back on it we did a whole bunch of stuff.   The most fascinating thing this week though was watching the students during independent working times.  They are talking about math.  They are asking for math.  They want problems to solve.  Some students are teaching algebra.  Some are very high level math students.  To watch them teach basic algebra to other students is amazing.  They want to learn!

One crew is on a quest to complete every Ken Ken puzzle around.  They started quite simple, but now they are doing the longer, much more difficult puzzles.  One character is even trying to make his own.  If you don't know, Ken Ken's are number puzzles in the form of Sudoku where you need to find the numbers in the boxes but by doing an algorithm such as adding, subtracting, multiplying, or dividing.  Click the links for more information.

Today's morning message problem came from my ride to work.  We were out of orange juice at our house.  I bought a 12 ounce container at Dunkin Donuts.  This container cost $1.70.  My regular half gallon orange juice container from Trader Joe's was empty.  The Trader Joe's juice costs $2.99.

How many Dunkin Donuts 12 ounce containers would I need to buy to equal one half gallon?
How much would that much orange juice cost?
How much less does it cost to buy a half gallon at Trader Joe's?
What is the price per ounce?

They started to work on the problem before our quiz today.  We are going to finish on Monday. I showed them both containers and one commented how math is part of every day. One said "How cool!" I told them that this is the stuff you can be thinking about while reading the cereal box at breakfast.  Each tiny piece of knowledge you gain will connect to another piece of information.

The thing I am most proud of this week was that every student can tell you how to find ten percent of any number.  Than to find twenty percent you just double the ten percent.  To find five percent you cut the ten percent in half.  To find fifteen percent, you add the ten and five together.  To find one percent you just move the decimal twice to the left.  A pattern will form.  It will always be a pattern. They will get to the point where they can find any percent of any number mentally.

No need for a tip calculator for these kids.

Next Week:  Unit test, Quick and easy decimal strategies, The facts reprised!


  1. Congratulations. It is a great move to get your students interested in KenKen. KenKen is about the best brain-training you can get on the fly, and it's so much fun that it is truly addictive.

    There aren't many ways to learn it beyond the simplest level, so I've put some free vids up at

    That should help them get their KenKen chops sharpened.

    Go figure!

    Brian (a.k.a. Professor Homunculus at )

  2. Ken Ken. That's a new one to me. Sounds like your kids are having a great time with math. Congrats.