A Learning Activity is a strategy a teacher chooses to actively
engage students in learning a concept or skill using a digital tool/resource.
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Phase:
During/Explore/Explain
Activity:
The students will create sounds and change the pitch to higher or lower by changing the length of the ruler.
Demonstrate the activity by placing a ruler on the edge of a flat surface so that part of the ruler is on the surface and the rest is extended past the edge of the surface. Hold the ruler steady with one hand by placing it over the part of the ruler that is on the surface and pressing down. Using your other hand, lightly pull up on the tip of the ruler up that is extended over the edge and listen to the sound it makes as it vibrates. Show the students how to adjust the length of the ruler hanging off the edge by sliding it in and out so that more or less of the ruler hangs off the edge. Lightly pull up on the ruler again. Call out the length in inches of the part of the ruler that is hanging off the edge, and ask students to predict how the sound will change. Stress the importance of pulling up instead of down. Pushing down will sometimes cause the ruler to break if there is too much force.
Pair off students and pass out rulers. Allow students to experiment with the rulers by changing the length of the ruler that is hanging off the edge of the surface as they pull up on the tip of the ruler. Remind them that to hold firmly the section of ruler that is on the flat surface, and pull up lightly on the tip that is extended over the edge of the surface.
Ask students which length sounds the lowest and why. Highest? Why? Discuss how the length affects the sound.
As students do the activity they will often begin to remark about how they can feel the vibrations in their hands as they pull up on the ruler. Ask them how the vibration feels when the length of the ruler is short. How does it change when it is long? Why do you think this happens? Discuss how sound waves are bigger for low sounds, creating slower vibrations, and smaller for high sounds creating quicker vibrations.
Have students work with a partner, to create a simple melody on their barred instrument and perform for the class.
Assessment Strategies:
Ask students to play their lowest pitch. Ask them how they know this is the lowest. Continue with highest. Ask students what needs to be done in order to change the pitch. Ask them to show you how to make it lower. Continue with how to make it higher.
Advanced Preparation:
Make sure you have enough space for students to manipulate rulers effectively on a table, bench, or bookshelf. Remove the metal edge from 12" rulers so they are easier to pull up.
Variation Tips (optional):
I often use this activity as a bridge to understanding high and low sounds on barred instruments like the xylophone. If you have barred instruments, demonstrate how sounds change based on the length of the bars just like the sound changed based on the length of the rulers. Have students identify the lowest and highest sounding bars. Ask them to explain why the bars sound low or high.
I use wooden rulers because they are sturdier, but plastic rulers could be used as well. Some students struggle with pulling up on the wooden rulers, so plastic rulers might be a better option for students with less dexterity, just remind them not to pull too hard.