Lesson: Metric Conversions
Do Now: Which number is larger?
1.1 or .1? Explain.
Rational: Many students struggle with decimals, so start off class reviewing them. Also, this unit occurs early in the year, so they probably need a refresher. Remind them that if the decimal is in front of the numbers then that number is less than one. Doing this will alleviate confusion and frustration in the future.
Next: go over some more example of numbers with decimals. Review.
Next: Present the PowerPoint (Metric PowerPoint Presentation). Preview presentation prior to presenting.
Next: Have students fill in the stairs on (Student worksheet 1) before modeling how to convert metric units. Show them how you can tell what the largest and smallest metric unit is, based on the presence and position of a decimal point.
Next: Model how to convert metric units by doing the first 2 examples on the (Metric PowerPoint Presentation) with the entire class.
I like to use the following approach with every conversion:
Example: Covert 10mm to cm.
1.) Have students look at their staircase. Ask: Are we going up or down?
2.) Ask: How many places do we move the decimal?
3.) Ask: Which direction do we move the decimal? Up the stairs = move decimal to the left, down the stairs = move the decimal to the right.
This is confusing because students think that if you're moving to a larger unit that the number should get larger. However, since the unit is larger the number will be smaller. For example: Let's use US measurement for a moment. Let's say that we have 10 inches, but we want to find out how many miles those 10 inches makeup. Miles are a lot bigger than a few inches, therefore, the answer will be a very small decimal. This explains why when you go from kilo to milli the number gets really big. It's just for the opposite reason: now the amount of smaller units that make up a larger unit is high, so this conversion will make the number larger.
Answer to example:
1) Up or down? Response: Up!
2) How many places? Response: 1!
3) Which direction do we move the decimal? Response: To the left!
Answer: 1.0 centimeters
After modeling the method used to convert have students complete the remaining questions on (Student worksheet 1) and then review. While reviewing have students state how they derived their answer. Have them state: "I went up, 3 places and I moved the decimal to the left. My answer is..." This will help ingrain in their memory the steps to convert metric units.
Checking for student understanding: Give students (Checking for understanding worksheet 1) and have them turn it in at the bell. Use this formative assessment to gauge the success of the lesson.
Homework: (Student worksheet 2) If there's time, students can begin working on this until the bell rings. They should finish it for homework.
It helps if students have learned about decimals and place values prior to this lesson. If they don't have this knowledge going in, just teach them the step system. However, if they have the required skills then you can teach them to multiply or divide. Students will need several days (at least 2) of practice with this, and, if you don't utilize it in class, they will forget. Therefore, make sure that you are incorporating this skill into lessons throughout the year.
|metricsystem powerpoint Notes||
|Checking for understanding worksheet 1 Assessment||
|Student worksheet 2 Classwork||
|Student worksheet 1 Classwork||
|metrics power point.ppt||