I think it is quite important to develop 21st century learners by using devices that will be a part of their work and academic lives, such as computers. I also like to use technology because I find that it increases my students' engagement.
For this lesson I open with the use of an interactive website. I like using interactive websites because they also are available for students to learn and work at their own pace. Students can return to the website at anytime to refresh their memory, check their work, and review their learning.
By fifth grade students should have some familiarity with protractors, but this lesson is designed for both new users and as a review. I'm using the website mathisfun.com. About half way down the geometry web page is a section titled Using Drafting Tools. Within this section is the link to Using the Protractor. On this page there are two introductory sections (Protractors are Fun and Easy to Use and Measuring) as well as a student practice section.
I review the two introductory sections with the students by showing the animations combined with student discussion (e.g., what did you notice), and reading the sections together. For the practice section, students work individually but are allowed confer with their neighbors.
If a computer lab is available it would be the best option for this lesson. If a lab is unavailable, you can use this website as a group activity as well; displayed on a projection screen.
Since the students are already in the computer lab or they have laptops out, we might as well extend their learning by another interactive website using their protractor knowledge. I found a great math game website that actually practices math concepts. This game can also be done as a class on the projector.
A lot of times with math game websites, the link to a math concept is blurred by the designers trying to make the game as fun as possible. With mathplayground.com I feel the designers of these games really thought about the concepts and created worth-while games to deepen the students understanding. This website is a little tricky though. There are several links to different websites on the main page. From the main page, you will just need to click on math games. This will bring you to the actual games associated with mathplayground.com.
As the students are logging off their computers and they are getting in line, I ask them to give me one thing they learned during their math time today. I have each student give me a quick response and then they are able to line up. I find that the students need to verbalize their learning as much as possible. I think it helps them solidify the concept in their minds and make a connection to their learning.