Thursday, January 24, 2013

It's All about the Boxes (Surface Area)

Vocabulary List from our Textbook
There are some parts of teaching that don't change, not many right now in education, but in math there are certain units that are always a challenge.  We just finished our polygon unit and have moved into solids. Most of this unit is brand new for my students, and they have limited background knowledge, so it's time for play which translates to hands on math.  

It's all about the boxes when talking about solids
For the first few years, I have to admit that I just "taught math" I struggled with going beyond the teacher's guide. Truth be known in math, the teacher's guide saved my life those first several years. But now that I am "more experienced" and I have had time to think about how to make math more hands on. I have some tricks up my sleeve that I pull out every year. Here is one of my best tricks!  

Cereal boxes are best for introducing solids. 

#1 have students bring in boxes to name and label them (count vertexes, faces, edges)

#2 cut out the boxes and define surface area and measure each section 

#3 build the box again and predict how many cubes will fill the box (volume)

Friends helping each other measure for surface area. Notice the Motts box?
Final answer for surface area for Frosted Flakes cereal.

#4 Finally I give the students some graph paper and they draw the nets and predict how many cubes will fit in their container.  As you can see in the video, she is holding her container and learned a huge lesson about volume.