When my husband and I lived in New Zealand for two years, we definitely had to get used to using the Metric System for everyday things like baking and paper size and recording our weights at doctors appointments.
But, as an architect, my husband LOVED using the Metric System once he made the leap from the (silly) system that he was used to here in the States (inches, feet, pounds, etc.).
At the beginning of the school year, I really drill how important it is that my students learn and understand the Metric System. This is a foundational science process skill that they will use all year long and for the rest of their ‘careers’ as students of science!
For some reason there seems to be a totally unfounded stigma around the Metric System.
Usually when they first see the words ‘Metric System’ on the agenda board, my students suddenly have a look of dread and start making groaning sounds. Little do they know how EASY it is and that as U.S. residents, they’ve been deprived of simple units measurement all their lives!
In this post, I am providing some ideas for teaching your science students how to use the Metric System!
Why the Imperial System is Silly
I have found it very effective to have students come to the conclusion themselves that the Imperial System of measurement is DIFFICULT, CONFUSING, and NOT INTUITIVE! This helps them to understand why we don’t use the Imperial System in science, and it also helps them to buy in to why they DO need to learn METRICS!
To help students see these truths, I provide them with the conversions for the Imperial System.
I tell them that for mass, one ton divided by 2000 equals one pound and one pound divided by 16 equals one ounce. They look puzzled.
Then they usually know that there are 12 inches in a foot and some know that there are 3 feet in a yard.
But then I share that there are 1760 yards and 5280 feet in a mile (what? why?!).
Then we get to fluid and dry volume. There are 4 quarts in a gallon and 2 pints in a quart. There are 2 cups in a pint. Okay. But then there are 16 tablespoons in a cup and 3 teaspoons in a tablespoon.
And one bushel of apples divided by 4 equals a peck of apples.
At this point they are like, “Where did these random numbers come from?!”
Well, to be frank, these numbers came from antiquated things like the length of the King’s foot and the size of a barleycorn. These relationships are completely irrelevant and random now!
By this point, they are hoping there is a simpler system. When I ask if they’d like to learn a simpler system, they’re all like, “Heck YES!”.
NASA’s Measuring Failure
Next I like to prove to my students that in the real world outside of the science classroom, people actually USE the Metric System. This is not something that they are memorizing for science class or some rote and irrelevant skill that they are being forced to learn that they’ll never use again.
This is a great time to discuss NASA’s big giant measuring failure. In 1999, because of an unbelievable math error, NASA lost its $125-million Mars Climate Orbiter!!!
Why?! Because spacecraft engineers FAILED TO CONVERT FROM IMPERIAL TO METRIC MEASUREMENTS when exchanging vital data before the craft was launched!
This video explains what happened. And this unfortunate and extremely expensive measurement mix up is a great introduction to the SIMPLICITY of the Metric System!
Breaking Down the Ruler – The Magic Number 10
Break out your rulers here! When I first started teaching middle school science, I skipped over this part of the lesson. I assumed that 13 year-olds know how a ruler works and how to measure the length of something. BIG MISTAKE. Most of them do not.
It’s a worthy investment to have a ruler for EACH student in your class for this part. You might even want to have little magnifying glasses to really drive home the big idea here. If you have a document camera in your classroom, use it! This way you can zoom in on the ruler increments.
Begin by pointing out that many rulers contain BOTH the Imperial AND the Metric System. They need to notice the ‘inches’ and ‘mm’ or ‘cm’ units on their rulers and double-check that they are using METRICS!
Next, have students use a piece of paper to trace their ruler and then use the ruler to carefully draw out all of the lines on the ruler onto their paper. They should now count the number of tiny (millimeter) lines in each centimeter. Review that the MAGIC NUMBER is 10!
King Henry Slider – Converting Between Metric Units
King Henry Died By Drinking Chocolate Milk. This is my personal mnemonic device of choice for the prefixes of the Metric System — the words of course stand for Kilo, Hecto, Deka, Base Unit, Deci, Centi, Milli. I call the process of moving the decimal point in numbers to the left and right “The King Henry Slider”.
So once my students memorize the prefixes, we begin doing ‘The Slide’. If you want to go from a smaller unit to a larger one, simply slide to the left! If you want to go from a larger unit to a smaller one, simply slide to the right! (Sounds like we’re at a wedding dance party, I know!).
To teach students to use “The King Henry Slider,” have them first write out the prefixes (KHDBDCM). Then, teach them to put their finger on the unit they are starting with and hop to the left or right to the unit they need to convert to, counting the number of hops. They’ll move their decimal place this many times in that direction.
Inevitably in every class, you will have someone raise their hand and offer that one could instead divide or multiply by multiples of 10 to convert between units. Yes, of course you can!
But, because of my totally mixed math-ability science classes, I find that this method gets too icky and stressful for many students. I like to teach them “The King Henry Slider” to keep them feeling successful and invested!
Accuracy and Precision
Here is a science process skill that a lot of teachers seem to breeze right over. But I drill this one because it’s simple but POWERFUL: understanding Accuracy versus Precision.
Many people would tell you that these two words mean the same thing but they don’t! So what is the difference and why is making this distinction even important?
- ACCURACY is how close a measurement is to the “true” or “accepted” value.
- PRECISION is how close a group of measurements are to each other.
Targets are a great analogy to use to help students visualize the difference between accuracy and precision. Here are the four scenarios depicted in the diagram above where I have thrown three darts at a target:
- ACCURATE but NOT PRECISE: My darts all land around the ring just outside the bullseye. I have accuracy (close to the bullseye), but not precision (my three darts landed in different spots).
- PRECISE but NOT ACCURATE: My darts all land far from the bullseye but they have all hit the same spot. I have precision (my darts landed really close to each other), but not accuracy (my darts are nowhere near the bullseye).
- BOTH ACCURATE and PRECISE: My darts all land right on the bullseye. I have both accuracy (I hit the intended target — the bullseye!) and precision (all three darts landed on the same spot).
- NEITHER ACCURATE NOR PRECISE: My darts all land in different random places far from the bullseye. I have neither accuracy (my darts are far from the intended target) nor precision (my darts are far from each other).
Students like this analogy because it’s simple and it makes sense. I like to show this TEDed video at this point too.
Now, getting back to the Metric System… how do we make accurate and precise measurements using metrics?
Well, accuracy is of course going to come down to knowing how to use the measuring tool (ruler, graduated cylinder, balance, etc.) and taking our time with our measurements.
Precision is going to mean we will be estimating one additional digit for every measurement that we make. But this is EASY using the metric system and this is the part that I DRILL!
If I measure a pencil and the graphite tip lands between the 17.5 centimeters and 17.6 centimeters mark, then my pencil is definitely 17.5 centimeters but it’s not 17.6 centimeters. It’s somewhere in between. I NEED TO ESTIMATE ONE ADDITIONAL DIGIT here.
This is where the magnifying glasses may come in handy! If I look closely, I can estimate that my pencil is about 17.57 centimeters. The “7” is the estimated digit that gives this measurement precision.
Now once I teach this mini-lesson, I expect my students to estimate one additional digit for every measurement they take from here on out whether it be for length with a ruler, for volume with a graduated cylinder, or for mass with a balance! I want them to get the hang of this so they begin doing this as good practice.
No Naked Numbers!
I like to DRILL this at the beginning of the school year because it applies ALL YEAR! There shall be NO NAKED NUMBERS in this classroom! In other words, every number needs to have a unit. We need to distinguish between 11 centimeters and 11 poke bowls, 297 grams and 297 zebras, 173 milliliters and 173 ways to say I Love You!
Teach the Metric System with Doodle Notes
Like what you’re seeing from the images above and think your students might too? Check out these Metric System Cornell Doodle Notes! These scaffolded notes will help you to explain these concepts. Not sure what Cornell Doodle Notes are? Check out this blog post to learn more!
80’s Party!: Measuring with the Metric Ruler
Now for the hands on. Let your students master working with length in metrics before jumping into volume or mass. The visual breakdown of the ruler will help them understand the increments and how they are related by the MAGIC NUMBER 10. They will more easily be able to apply this to understanding metric volume and mass!
This fun FREE ’80’s party’ measuring length activity has students measure various objects on a piece of paper and then around the classroom. This activity also provides students a chance to practice making BOTH ACCURATE and PRECISE measurements!
The students use the metric units of millimeters and centimeters. They need to pay attention to which unit is requested. While ‘getting ready for the party’, students make 20 measurements of length of objects on paper.
Then, students measure actual things in the classroom. This part of the activity depends on what materials you have available.
Grab some mustaches, party hats, fake glasses, beach balls, and other toys from your local dollar store! Put all of these items on a few tables in your classroom and either tell the students what they should measure or have the students choose items to measure in whatever way they’d like. For example, they may choose to measure the diameter of a party hat, or the circumference of a beach ball (they will need string for this!), or the length of a faux mustache.
This is the time to really STRESS PRECISION! For every single measurement, students should be ESTIMATING ONE ADDITIONAL DIGIT!
Color Fashion Show Challenge: Measuring with the Graduated Cylinder
This activity is so much fun to do at the beginning of the school year. It helps students to practice measuring with graduated cylinders in a creative way.
Students use richly-colored water in the primary colors (red, yellow, blue) to create new secondary shades (orange, green, purple). This is an inquiry with just one parameter: their secondary colors’ volume MUST be 25 mL. So for example, they could try mixing 12 mL of red with 13 mL of yellow to make an orange, then they could try 10 mL of red and 15 mL of yellow to make a different orange.
They will create at least 3 shades of each secondary color and write down the quantities of each color in the provided data table.
After experimenting and creating 3 to 4 shades, each group will choose its favorite shade of orange, green, and purple to use for its Rainbow Rack.
Once each group of students has created a new ‘Rainbow Rack’ containing the primary colors and three new secondary colors, then they use these colors to create their ‘designer’ colors! For example, they might create colors called ‘Purple Haze’ or ‘Tiger Lily Orange’ or ‘Jupiter Red’. They write ‘recipes’ for the colors that they create. Students collaborate and share their designer color recipes on a Google Sheets data table.
You can host a Designer Color Fashion Show and have your students share and vote on their favorite colors!
Mass Mini Labs: Measuring with the Balance
Once my students have mastered measuring length and liquid volume using the metric system, I jump into mass with these Mini Labs activities!
First, I teach my students how to properly use a triple beam balance. They have to understand how to read the rider values and how to estimate one additional digit to make a precise measurement using the balance. Then, three fun hands-on mini labs allow them to practice their measuring skills!
For the “Bowl of Fun!” lab, I gather fun random objects from the dollar store (this usually falls in October so I try to include Halloween themed objects like mini jack-o-lanterns and spider rings!). The students practice making precise massings of objects of their choice from the bowls!
For the “Clay Creations” lab, I give groups of students a hunk of modeling clay. They work as a team to build a creation, continually adding to the figure and massing it six times. They find the average mass of the clay that was added each round. This is great practice to review finding an average.
For the “Small Change” lab, I provide the groups pennies from various decades. They find the average mass of their pennies, compare it to the average of other groups’ pennies, hypothesize why the averages are so different, and design an experimental procedure to test their hypothesis. This is a fun way to review the scientific method, also!
I hope that these ideas and activities help you to relieve your students’ anxiety about the Metric System! I’d love to hear more ideas that you have for teaching the Metric System in the comments below!
You may also be interested in checking out this bundle of resources, which includes the hands-on activities above, plus Cornell Doodle Notes on The Metric System and Measuring Length, Volume and Mass! By the way, the Cornell Doodle Notes contain the doodles included in this post!
No Comments