To open this lesson I show students a video that discusses powers of ten - from light years away to microscopic electrons. Using video in the classroom is an effective tool, if students are held accountable. By reviewing this video first, I'm prepared to stop and start the video in order to activate discussion and ask probing questions. I want my students to come away with a feeling for "the power" of ten.
After showing the video I ask students to make inferences about the math concepts that are covered in this clip.
I explain to students that the math concepts covered in the video will assist us in our understanding and mastering of our I can… statement from yesterday.
Let’s remind ourselves of the I can… statement. I’ll say it, then you repeat. I can explain patterns when multiplying a number by powers of 10.
Because the purpose of this lesson is to have students understand powers of ten, I focus on showing students how to divide tens as reciprocals instead of decimals. Decimals are covered in future lessons within this unit and will be addressed in depth at that time. Although fractions are also a difficult concept for students, I think the use of them in this is lesson is more effective.
I show students several examples of how to divide numbers by powers of ten. For example, 1 / 102 = 1/100 (as a fraction). Or, 64 / 103 = 64/1000 (as fraction). I then ask students to work within their groups to ask each other questions similar to the ones that I just asked them. I have the students use their whiteboards to record their responses that the group member is asking them. I circulate the room and monitor for misconceptions while students are working.
The end of this lesson is a worksheet, that I have students complete on their own. I will use it to check for overall understanding of powers of ten. I found this sheet on the Math-Drills website. Love it! This worksheet incorporates both multiplying and dividing by powers of ten.
I use the information gathered from correcting this worksheet to determine if further lessons are needed to deepen the students’ understanding of powers of ten.
After reviewing students' work on this worksheet, I was pleasantly surprised. Students did relatively well on this informal assessment. I was satisfied with the work I had seen and felt confident in their knowledge of powers of ten at this point in the unit. There have definitely been times that I have done this type of informal assessment and found that students did not understand the concepts. In times such as these it is a good idea to take a step back and evaluate how you taught and what you taught. Sometimes we think how we taught something was effective, but if students are not showing progress maybe another way of teaching the concept could be utilized. The most important thing I remind myself is to not give up. Find another way! We must adapt to our learners just as organisms adapt to their environment.