Surface Area and Nets

          I always enjoy teaching surface area because there are so many great ways to make it concrete for my students.  In order to build conceptual understanding, students need to be able to physically touch and build polyhedra.  In sixth grade math, we focus on the surface area of rectangular and triangular prisms (http://www.corestandards.org/Math/Content/6/G/A/4/). 
        The lesson began with a video from Andrew Stadel's Estimation 180 collection called "File Cabinet." (http://www.101qs.com/518-file-cabinet--act-1) I warned students that it might seem strange, but Mr. Stadel was going to cover the cabinet with sticky notes.  They would have to figure out how many sticky notes it would take to cover the cabinet. 
Image result for stadel filing cabinet
Source: Andrew Stadel http://mr-stadel.blogspot.com/2012/04/file-cabinet.html

      My students' reaction was priceless - despite the somewhat silliness of the task!  They made lots of great connections and observations.  Here are a few of my favorite comments:
              "Wow!  I totally get it!"
               "I finally understand why it's called square units on area."
                "This is sooooo cool!"
I love that my students were so engaged and connected with this lesson.  We kept the momentum going by moving to finding surface area using linking cubes.  They were able to the square faces of each cube to count the surface area of their rectangular prisms.  Lastly, we moved to finding the surface area by moving from solids to the corresponding nets.  

Students drawing and using nets to find surface area
    Anything we teachers can do to make math more visual will help to build understanding and retention in our students.  Using manipulatives can be a great way to adapt/accommodate assignments and assessments for students with IEPs.  So break out the sticky notes, linking cubes, and graph paper and have some fun!

Comments

Post a Comment

Popular posts from this blog

Understanding Units

Image
Inches, Square Inches, Cubic Inches     In high school, geometry was my nemesis too, so I completely understand how easy it is for my students to be confused when it comes to labeling answers.  We spent a lot of time early in the year learning about area and surface area.  I think this made it difficult for my class to then understand a linear unit.  When they would have to count the length of a side of a polygon draw on a grid, they would often incorrectly count the squares inside along the length.  To try to help students differentiate between linear, square, and cubic units, I broke out a set of pipe cleaners.     Although a bit floppy, the pipe cleaners served as a good way to model the three different units of measure.  Students went around the room and found various objects to measure and the most appropriate unit with which to measure.  This activity helped students to use the correct unit of measure and led to productive ...
Read more

Intervention Groupings

     Each year I teach a math intervention course.  This course runs for about 25 minutes, so I don't get very much time to work with my students.  I have to make every minute matter, so each day is very carefully structured.  But this can be very hard to do!  What skills should I cover? Do I have time to get out the manipulatives?  Are number talks worth the time it takes to do them?     I have found a few things do help to make the intervention time successful.  First of all, keep the number of students relatively small.  Less than 20 students is ideal, but under 16 is even better.  When the class is too big, it is very difficult for every student to have a voice.  I need to make sure that I have an opportunity to interact with every student, so keeping the numbers small is important.      Secondly, ditch the worksheets!  The drill and kill approach to reviewing material is ineffective.  S...
Read more