Micheltello, the Fifth Ninja Turtle

The Activities

1. Topic: Story Problems: Book: How High Can a Dinosaur Count? …and Other Math Mysteries by Valorie Fisher.
2. Topics: Codes, Combinations, Story Problems: We created a Teenage Mutant Ninja Turtles “adventure” with three stages.  All materials for this activity can be found here.  The story is that Shredder has discovered some ancient machines that, when activated, will cover the world in slime (I printed out some pictures of the characters for those less familiar with ninja turtles).  The turtles obviously want to stop him, and they find Beebop and Rocksteady, defeat them, and take from them a coded message from Shredder.  This was a number-letter substitution code, but unlike in the past, I did not give them the key.

Deciphered message

Then I said that Splinter remembered a legend of an ancient fifth ninja turtle, but he couldn’t quite remember his name.  However, he did remember that the name was a combination of two of the first four turtles’ names (e.g., Raphangelo).  If they can list out all the possible names, he will remember.

Now that they know the fifth turtle’s name (Micheltello), April O’Niel goes on TV and says that Micheltello should come help them.  He shows up, and says that that he knows where the slime machines are.  The turtles go to the slime machines, but each one has a story problem that the kids must solve in order to turn it off (see link to PowerPoint above for the story problems).  Once they solve the problems, the world is saved and the mayor gives them each a prize!

3. Topic: Origami: We made the pinwheel from Easy Origami by John Montroll.

How Did It Go?

All six kids attended.  This circle went well, all the kids were engaged the whole time — having a theme definitely helps.

How High Can a Dinosaur Count?

This book has a bunch of story problems, mostly about addition but a few others, including a couple about money.  Most weren’t too hard for them, but they usually couldn’t solve them instantly.  I had the kids raise hands to answer, all the kids gave at least one answer.  The hardest one was to count up how much money two dimes, two nickels, and three pennies was.

When I first announced the topic, one of the girls said “I’m not interested in boy things.”  Fortunately, once we started working on the problems, she jumped right in :).

The first breakthrough for the code was that one kid said that one of the three letter words could be “the”.  I pointed out there were several three letter words.  They noticed that two of the four three letter words were the same, and tried filling in “the” for that one (which was correct).  They made a bit more progress after this but then got stuck.  One kid kept asking “What are the two little dashes at the bottom?”  I just said “Part of the message.”  Eventually, that kid said “Maybe this says Shredder!”  They didn’t quite get the concept of making sure the pattern of the word worked (they certainly didn’t notice that certain words had double letters until after they filled them in).  Once they got Shredder and filled in the matching letters elsewhere, they guessed “turtle” and “ninja”, and got most of the rest.  They ended up having the whole message decoded except for “_i_th”.  One kid suggested “ninth”, but n was already used.  I suggested they try similar things, and they got “fifth” after a bit.  I had the kids take turns being the writers, since they all wanted to fill in the letters (4 kids writing at the same time is pretty tricky).

They were slower than I expected at generating names.  In similar activities in the past, there’s usually been a flood of suggestions, but I guess the concept of combining a prefix and suffix was trickier.  However, almost immediately, one of the kids suggested drawing a line between the prefix and suffix whenever they thought of a new name.  This was obviously extremely helpful for searching, although they still weren’t that good at that.  After a while, a different kid noticed there were a different number of lines coming from various suffixes, and found things to even it out.  However, they still didn’t realize there needed to be three coming from each one; after a while one of the kids suggested there should be four lines, but I pointed out that you wouldn’t have one for the actual real names, so only three.  All the kids came up with at least one name and wrote it on the chart.  This was the first time in a combinatorics activity that I think they had some concept of having found the all possibilities.

The story problems were somewhat difficult, in particular, understanding what the problem was asking was sometimes tricky.  Their reading is pretty good, but long complicated questions are still difficult.  I had to help almost all the kids understand their questions.  About half the kids finished their own questions fairly quickly, and then I had those kids help the others with their problems.  There some interesting incorrect answers.  For the problem “There are 17 pizzas with 10 slices each, Michelangelo eats one slice from each pizza, how many are left?” the initial answer was 7 (17 – 10).  When another kid came to help, they realized it should be 9 * 17.  I suggested that they might take the initial pieces (170) and subtract the eaten pieces (17), which they could do.  Another interesting problem was “Leo has 2 swords, Raph has 2 sais, Dona has 1 bo, and Michel has 2 nunchuks.  Also, each turtle has 3 ninja stars.  How many total weapons?”  The initial answer was 10, adding all the numbers in the problem.  So, there’s clearly room to improve in translating story problems into math expressions.

Origami

The pinwheel wasn’t too bad for them, we can probably do something harder.  But the final step where you pull out the points was tricky for some of them.  One of the kids was eager to tell me that she could make an origami dragon, but we didn’t have time for a demonstration.