I have to give a shout out to Mathalicious lessons right now.  I’m impressed with the way the student sheets are structured.  The directions are very clear and accessible to students so they can get right to work without tons of questions or further explanation from me.  This allows me to walk around and observe so I can see where my students are and help the ones that are struggling.  The questions also progress in the lesson so that students use their previous work to make discoveries.  This is really tough to do when creating lessons.  Kudo guys!

I did the Mathalicious lesson New-tritional with my 7th grade students.  I started with the opening slide and had them notice and wonder for a few minutes to see what they know.  They immediately got that it took 54 minutes of running to burn off the 550 calories in a Big Mac.  After watching the video, we talked about the preview questions (which I love btw)!  What factors affect how many calories we burn, how many calories do they think are in a big mac meal, and how long do they think LaBron would have to play to burn off that whole meal (if he had actually gotten to eat it)?

We then did Act 1.  I stressed UNITS!!  My lesson focus was functions, not decimals so I let them use calculators.  If I did this lesson in 6th, my focus would have been decimals and I would have them calculate it by hand.  Even with the calculator students said, “There has to be a quicker way to do this.”  FORESHADOWING!

A great discussion about the commutative property of multiplication came up in question 3 as students multiplied in different orders and got the same answer.  Then, I went back to their “easier way” remark and gave them two minutes on my timer to silently think of a better way to do all of this work.  After two minutes they shared their strategies with each other and then we discussed them.  I had listened in (Five Practices) and picked groups of students to go in order from least to most algebraic.  Rounding the cal/min was a suggestion by a couple of students.  But others pointed out that is wasn’t very accurate.  Several students wanted to graph it, and finally, a few even said that we could write a function.  Bingo.

So, as they suggested, we started with a graph on Desmos.  We entered the weight, and then the cal/min of the activity.  In the 2nd class, instead of entering (125, 7.875) in the Desmos table,  125, (125)(0.063) so they could see the pattern without me having to re-write it on the board.  After entering in all of the basketball data, I connected the dots.  Of course they wanted to extend the line, but could not from just the table.  They knew they needed a function so I gave them two more minutes of silent time to just LOOK at the table and see if they discovered the pattern.  No lie, almost every student was able to write the function, for the win!

When I typed the function in and the red line drew on top of our line segment there were gasps in the room.  Oh, how I love it when these magical moments happen in math class!  We then use the weights of student volunteers to see how many calories per minute they burned playing basketball.  We found it on the graph, but then I created a table from the function and they loved that even more!

The question “How many calories do you burn just sitting?” came up and another student exclaimed, “IT’S ON THE BACK!!”  A student commented that he didn’t even burn ONE calorie per minute by sitting!  Which made another student ask, “How much would you have to weigh to burn one calorie a minute sitting?”  I had them write the “sitting” function  f(w) = 0.009w.  Then, I wrote f(w)=1.  So that 1 = 0.009w and we just solved for w, then check the answer in our graph.  I love it when a week comes together this way!!

Bonus – Student Remarks:

• That picture isn’t real food.  McDonalds has an artist make food sculptures that they photograph.  (Really? I had no idea)
• Who is that old guy? (Larry Bird)
• Oh yeah! I thought it was Clinton too! (After telling them of Elizabeth’s students.)
• I bet LaBron burns more calories per minute than that playing basketball since this is an average.
• How many calories do you burn sleeping (volleyball, jumping on the trampoline…)?
• How many calories do you burn just sitting – OMG, It’s on the back!
• How many calories do you burn thinking.
• Thinking? That’s JUST sitting.

Thanks again Mathalicious for a great day!