Measurement and measurement conversions are tricky for everyone…adults included…I’m the worst when it comes to ordering groceries and not paying attention to the size of what I’m buying 🙈Ever bought the world’s smallest tube of toothpaste?! Or the biggest container of dish soap that exists? I have 😂
When it comes to teaching measurement conversions, my thoughts around this are pretty similar to everything else I preach about teaching math…NO TRICKS. I know there are many silly mnemonics out there (King Henry and his chocolate milk or something like that 👑🥛) and songs about horses and flies 🐴🪰 to try to help students remember when to multiply and when to divide…but those do nothing but confuse me…as an adult. And if they confuse me as an adult…I will not be teaching them to students.
Instead, I use a tool and strategy that they are already familiar with. Let’s get into it!
Building the Foundation
First things first, students need experience with measurement units in general and their relative size. They need a basic understanding that an inch is smaller than a foot and a foot is smaller than a yard. They should also know about how large a measurement unit is. For example, a meter is about the length of a baseball bat and a gram is about the same mass as a paper clip.
Give them time to explore measurement units with real life objects. Bring in different size liquid containers, give them a ruler and send them around the classroom to measure. This is the foundation of them being successful with other measurement skills we need them to have.
Looking for resources to introduce relative measurement? Check these out.
STAAR Reference Chart
Let’s take a quick pause before we dive deeper into what this looks like. In Texas, students have their Reference Charts that they are allowed to use on the STAAR test. Hopefully students have seen this at some point during the school year. Now is the time to have that thing out all day, every day! Students need to get used to constantly having it with them and referring to it. I like to print a copy for each student on bright colored card stock. Then, I have them give it a name (and write it on the reference chart!) because it is their new best friend! I also have them write their own name on it as well…which is super fun when because then I can say things like “Oh sweet Spongebob, Robert left you sitting on the floor!” 🤪 “Oh there you are Captain Glitter Farts, Caroline has been looking everywhere for you!” But seriously! Make it fun! They keep it in their math folder, and we use our best friend to help us in math every day from there on out.
Connecting to What Students Already Know
Back to our regularly scheduled programming. Chances are measurement is one of the last concepts you teach during the school year and we are going to use that to our full advantage. My favorite way to teach measurement conversions is using an input-output table. This takes concepts of patterns, multiplication, and division and helps students connect this to the new concept of converting between measurement units.
With measurement conversions, I recommend starting with customary length as it is one that students are most familiar with. Then, we can move on to converting any and all units of measurement. In this blog, we are only going to discuss converting within the same measurement system.
Let’s start with converting 4 yards to feet. Students should know that a yard is bigger than a foot. Look at their “best friend”/reference chart, they should also know there are 3 feet in 1 yard. When teaching students to use their reference chart, I make the whole class point to where they see yards and feet. Even if they think they already know there are 3 feet in a yard, we are all going to find it on our reference sheet.
We are going to set up an input-output table. Label the top with the unit we were given (yards) and the unit we want (feet). Then we will fill it in with the information from our reference chart 1 yard = 3 feet.
Next, we identify the rule. How can I use multiplication or division to get from 1 yard to 3 feet? The rule is times 3– 1 yard times 3 is equal to 3 feet.
Then we can do the same thing to the 4 yards we are wanting to convert. Place the 4 on the yards side of the input-output table, then follow the rule. Four yards times 3 gives us 12 feet.
Once students master customary measurement conversions, metric conversions are a piece of cake. Everything is multiples of 10! Why in the world do we still insist on using the customary system?!? 😅
You will also want to make sure students practice conversions with measurements of time such as weeks, days, seconds, and hours.
The last kind of problem we have to introduce students to are multi-step conversions. For example, if I want to know how many pints are in 3 gallons, you’ll first need to convert gallons to quarts and then quarts to pints. This will involve using 2 input-output tables. The first table will have gallons and quarts at the top and the second table will have quarts and pints at the top.
Next, we will follow the same steps as mentioned above, one table at a time. We will use our reference chart to find out the relationship between gallons and quarts. Then we will convert our 3 gallons to quarts. Then, we will move to the second input-output table to convert quarts to pints.
Wrapping it up (+2 FREE resources!)
You can watch measurement conversions using input-output table in action here and here on Instagram.
Measurement conversions can feel like the ultimate brain buster for kids (and definitely for us grown-ups who’ve accidentally bought the world’s largest bag of beans). But with a solid foundation in the sizes of each unit, a well-loved reference chart by their side, and input-output tables to tie it all together, your students really can—and will—become measurement pros.
To help you get started, I’m sharing two FREE resources:
- A worksheet for practicing conversions with input-output tables. 4.8B Measurement Conversion practice
- A “Would You Rather” (WYR) style activity that brings an extra dash of fun to measurement problems! Measurement Conversions Would You Rather Mini Set
These freebies are designed to give your students the concrete, no-tricks approach they need to master measurement without all the confusing songs, rhymes, or gimmicks. Grab them, try them out in your classroom, and let me know how it goes!
