Surface area is a such a fun topic to explore in the middle school math classroom! To really understand what surface area means, students need to interact with actual three-dimensional objects. Before we talk about the math formulas or how to calculate, we spend time discovering how to find surface area in our own ways.
I give students every-day items to work with. Typically, we use product boxes (rectangular prisms) with different dimensions, and I ask the students to visualize and then draw what the boxes would look like if they were taken apart and laid flat. Most students take about 5 minutes to complete their drawings, depending on how detailed they choose to be, and for the most part, they do a very good job drawing the nets of the boxes. Next, I have them spend a few minutes comparing their nets with group members, deciding whether those nets are reasonable representations of the object (even if they are drawn a little differently), and determining whether anyone appeared to be missing anything (some students will draw only five sides, and their group members are able to help them figure out what's missing).
After drawing their nets, I assign the groups two tasks - to find the surface area of their particular box and to determine a formula for the surface area of rectangular prisms. At this point, we have already studied area, so the only thing we discuss before they set upon their tasks is the actual meaning of the term surface area....we brainstorm the possible meanings and agree on the defintion. Then they set off measuring and calculating.
Hi, I'm Ellie! I've been in education for 25 years, teaching all subject areas at both the elementary and middle school levels.