Introduction to Metric System

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The students will be able to define the seven parts of the Metric system units and convert amongst them.

Big Idea

King Henry Died Unhappy Drinking Chocolate Milk!


15 minutes

Today students will be introduced to the Metric System of measurement.  They will hear a story of King Henry containing a mnemonic to help them recall the parts of the Metric System.  Students will create a foldable for the Metric System and then use it to practice converting amongst the units.

There are a few different examples of the King Henry mnemonic but I like this one the best because it contains a spot for the word Unit.  I think it is important to leave a place for this because it can easily be forgotten by students.  The mnemonic is King Henry Died Unhappy Drinking Chocolate Milk. 

I begin today’s lesson with The Story of King Henry, a funky story to illustrate the mnemonic that I modified from Clark Elementary in Tampa, Florida.  This Powerpoint contains the fictitious story of King Henry and his love for chocolate milk.  After the story there are a few examples that we will work through as a class.  The goal today is to learn the prefixes associated with the Metric System and how the decimal moves when converting. 

I go through the slides with the students and offer pauses for the students to share their thoughts of poor King Henry.  When I get to the 7th slide, which features the prefixes for the units, I spend some time having the students say the prefixes with me a few times.  We slowly go through the remaining slides which contain examples.  I leave the last slide displayed on the projector as we move on to creating our foldable.


30 minutes

I use a lot of foldables in my room.  I think it is a great way to keep and record important information across the curriculum.  The foldable we will be creating today is a little different from the standard foldable.  It takes a little more effort to make but the kids will really enjoy it. 

I have included a video that creates this foldable step by step.

I show students how to create the foldable and then have them go back and add the prefixes to the steps of the foldable.  Once the students are finished creating and labeling their foldable I show them how we are going to use it to help us convert between measurements in Metric System.

Alright, now that we have this tool, let’s figure out how to use it.  If we are going to convert from unit to centi-unit how many steps do we have to cross?  Show me with your finger on your foldable where the decimal started and where the decimal ends.

It is important that students visualize where the decimal begins and ends.  I do a few more examples with just looking at the foldable and then we try some examples with numbers.

Okay so now let’s take out our whiteboards and try writing a few examples down.  On your whiteboards please write the 435 centi-unit.  Right now we are not going to worry about what type of unit we are using. 

If we wanted to convert 435 centi-units to hector-units how many steps will we have to cross on our foldable?  (4)  Alright let’s move the decimal 4 places.  Where is the decimal in the number 435?  Okay so that’s where we have to start.  With your marker let’s do 4 decimal jumps.  So your new number is 0.0435 hecto-units. 

Think back to powers of ten, what does it mean when the decimal can jump from side to side?

I want students to make a connection between powers of ten and the Metric System.  I want them to see that as you move places to the left you are dividing by 10 and when you move places to the right you are multiplying by 10. 

I go through a few more examples with the students writing down the numbers on their whiteboards. 


15 minutes

To wrap up us this lesson I have students do a word sort of the prefixes of the Metric System.  I give each student a copy of the seven prefixes and have them cut the words up.  After the students finish cutting I ask them to shuffle the papers up and then put them in order from left to right.  It is important that students assemble the words with kilo on the left and milli on the right.  Once they have done it by themselves a few times, I make a game of it. 

Alright this time I am going to see who can do it the fastest.  Everyone mix up your pieces and lay them face down in a pile in front of you.  When I say go you are going to organize the pieces into the correct order.  When you think you are finished and have it correct shout out Metric System and stand up.

I play this quick game with students a few times then end the lesson by asking students to summarize the story of King Henry with their neighbor.