Skip to main content

KenKen

Over the March Break (when I had some unstructured down time) I ran into a new puzzle form -- the KenKen. While it has a superficial similarity to Sodoku in that the numbers can't be repeated in a column or row that's where the similarity ends. In KenKen, the large grid has been broken up into cages - highlighted areas that have to be filled in with an arithmetic expression to hit the target number written at the top of the cage. There is also an arithmetic operation at the top of each cage. So, for example, if 24 x is at the top of the cage, the cage would have to be filled with as many numbers as cells in the cage and those numbers would have to multiply to 24 (so it could be 2x3x4 or 4x6 depending on the number of cells in the cage and the restriction against repetition, of course). As an exercise in class, it's a good reinforcer of basic skills (no calculator, of course). Once my students have the hang of completing the puzzle, we're going to move on to constructing our own. As always, it's harder to create.
My only concern about KenKen is that it treats subtraction and division as commutative. That is, it treats 6-4 and 4-6 as the same answer, 2. I wish the KenKen authors would use Polish (or pre-fix) notation so that it would avoid this issue. Plus it would allow us to talk to the students about Polish notation. When I went off to university I bought my HP28 ... it was one of the first graphing calculators and, as all good HP calculators did, worked in Reverse Polish Notation. That is, when adding 2 + 3 you entered it 2 3 +. The operation would always go at the end. It means you don't have to use brackets to avoid order of operations. A great little calculator I used until I became one of the testers for the TI82. But that's a story for another day.
Reblog this post [with Zemanta]
Post a Comment

Popular posts from this blog

Teacher Professional Development and Microsoft OneNote

During the first three weeks of July, I have the amazing opportunity to work at the Park City Mathematics Institute.  It is, without exaggeration, the best professional development opportunity for teachers of mathematics.  Participants spend three weeks thinking deeply about mathematics and mathematics education.

There are three main aspects of PCMI:

learning mathematicsreflection on practice (RoP)becoming a resource to others.I'm part of the team for RoP and in charge of the third aspect, in which participants consider a gap in professional development back at their home districts and work in small groups to help fill that hole by developing a rich PD seminar on that topic.

It is not easy to develop professional development.  Teachers who haven't written PD have to patiently learn how to write (essentially) lesson plans for someone else.

This year, I used Microsoft OneNote to facilitate the process.  We have a central OneNote Notebook through which I lay out the daily schedule…

Five reasons to learn Math with OneNote

So, Alice Keeler - @alicekeeler- who is an amazing blogger and an incredible resource for those using Google products, posted 60 Ways Math Teachers can use Google Classroom last April.  It came across my desk the other day and, since school hadn't started yet, I thought it might be a good reflection for me on how one could do similar tasks with OneNote Class Notebook.

I went through the list and checked that I could accomplish them all with OneNote and re-wrote her post with those modifications ... but it was looking a little "plagiarism-y" so, just to check, I emailed Alice to see if she was okay with it.  She was not, but encouraged me to do my own brainstorming.
So... Math Teachers & OneNote (including OneNote Class Notebook).  My top five... 
1) The Under-valued value of scribbles & notation
If you really want to be "paperless" (and that should never be a goal - you want to be digital so that content is no-cost) in a mathematics classroom, it's n…

Auto-Grading an Office365 Excel Survey Assessment

So it's pretty common that folks use Google Forms to create an automatically graded assessment.  Now, I have to admit, as a mathematics teacher I don't do a lot of fixed-response assessments like this that need automatic grading.  But that doesn't mean it isn't a useful option.

In fact this post arises not from automatic grading but rather a situation in our Psychology course.  The teachers were doing a study with their students and wanted to collect the data easily and run a T-Test with as little work as possible.  (A t-test, roughly speaking, determines whether two groups are different from each other.)

We set up an Excel Survey for the students to enter their results and then in a second sheet in the spreadsheet containing the Survey, we laid out the T-Test.  As the results came in, the T-Test continually re-evaluated.  Success!

I figured if it can work for a T-Test, it can work for a simple multiple-choice, True/False or simple word response. So I head over to my O…