Rounding numbers is a key concept in mathematics that every student will encounter repeatedly, especially in upper elementary. At first, we introduce whole numbers: “round 27 to the nearest tens place,” “round 561 to the nearest hundred,” and so on. Eventually, your students will move on to decimals, where knowing how to round is an absolute necessity. No one wants to be calculating pi using its infinite digits!
On its surface, rounding seems like a straightforward concept: round up if the number is five or higher, and round down if the number is four or lower. While this certainly holds true for us as adults, it can be a bit tricky for kiddos! Not only that, but simply telling students “this is how it is” doesn’t really do them a whole lot of good. We want students to understand the how and why of math concepts in order to build number sense and a strong foundation for their math careers.
There are plenty of great resources in the educational sphere that promise to help students grasp rounding, such as mystery cards or mixed-up math pictures, but in order for these activities to be effective, your students need a strong foundation that only you can provide. Thankfully, there are several methods you can employ to do so!
With that being said, how can we show students the importance of rounding and help them understand how it works? There’s more to it than just writing numbers and arrows on the whiteboard, right? Luckily, visual models and diagrams can come to the rescue! We already know just how important it is for students to be able to visualize math concepts, especially those that seem more abstract. Drawings on the whiteboard aren’t just for science!
By incorporating these tools into your teaching, you can make rounding numbers engaging and more meaningful. Students with a strong understanding of the concept are much more likely to have a smooth transition into decimals and other adventures on their math journey. However, before we launch into strategies for teaching rounding, let’s look at its importance!
Why is rounding numbers important?
When you think of rounding, you likely picture an arbitrary number being moved up to its nearest hundred. However, rounding isn’t simply a mathematical operation that makes decimals easier to work with; rather, it helps develop number sense and encourages students to explore how numbers relate to one another, which leads to effective problem solving!
In that same vein, let’s take a look at some ways to ensure these skills are getting through to your students.
1. Building Number Sense Through Rounding
Like I’ve said plenty of times before, number sense is one basic skill that kids need in order to understand how numbers relate to one another. I’ve posted before about steps to build number sense as well as shared several strategies that boost number sense, and rounding is no exception! We can take these blueprints and implement them here: by using visual models, students can explore how it works and see specifically where numbers fall on a number line. This, in turn, fosters an intuitive understanding of numbers and their relationships.
2. Enabling Effective Problem Solving
In addition, visual models and diagrams can also make the process of rounding numbers more interactive. Of course, these tools allow students to manipulate numbers and see how rounding affects the outcomes of different problems. It makes abstract concepts tangible and facilitates problem-solving skills. In other words, you’re teaching math so students can get it! That sounds like a win on all fronts, don’t you think?
What are some visual models and diagrams used to teach rounding?
Now that we’ve covered the far-reaching effects of a valuable foundation, let’s get into the good stuff: what are the best visual models and diagrams that you can use in your classroom? There are plenty of examples out there, but thankfully, I’ve done the hard work for you. I’ve tried so many strategies to teach this “basic” concept, and determined that the best models are those that allow your students to visualize and apply the numbers to real-life situations. With that being said, let’s explore my favorite and most well-received visual models and diagrams that work best for learning to round!
1. Number Lines
Let’s start with one of the most popular tools for teaching kiddos to round: number lines! Number lines visually represent numbers, allowing students to see where a number falls in relation to others and how rounding it up or down affects its position. Students can physically mark the numbers and see the process in action. There’s a reason why number lines are so popular–they work for all sorts of number goodness, from rounding to fractions.
In addition, a vertical orientation of a number line can be helpful in showing how numbers move up or down when they are rounded. It can be an engaging variation to the standard horizontal number line.
Number lines are also an excellent resource to use when diving into rounding fractions to the nearest whole number. Whether you’re finding rounding solutions or simply representing numbers, number lines are the way to go for mathematical operations made easy!
2. Place Value Charts
Place value is arguably the most important concept students need to grasp in order to develop a thorough understanding of rounding. Thankfully, if your students have a good foundation of place value, you’ll be good to go! Of course, if you need a little more oomph in your place value lessons, that’s okay too; just head over to my post on engaging ways to teach place value to get started.
Once your students have a hold on place value, try using place value charts in your exploration of rounding. Place value charts encourage students to explore how each digit in a number has a different value. In addition, by highlighting the digit to be rounded and demonstrating how it affects the other digits in the number, your students can also visualize the process of rounding.
3. Rounding Coaster
One of the greatest strategies for rounding has been around for a long time, and for good reason–it’s a great visual! Commonly referred to as “rounding hills” or “rounding mountains,” these diagrams are shaped like hills where the peak represents the midpoint that determines whether a number should be rounded up or down.
Students can “climb” the hill with a number and see where it lands. As you can see above, I refer to this diagram as the “rounding coaster” to make it a bit more fun. If you really want to engage your kiddos (and maybe make your neighboring classroom jealous), you can even go over a few examples while pretending to be on a roller coaster. Are you sliding backwards, or are you flying forward down the hill? Put your hands in the air and cheer!
4. Real-Life Context Diagrams
We’ve seen a few ways to visually represent rounding; now, how do we make rounding numbers meaningful? One way is through creating diagrams or visuals that connect rounding to real-world scenarios such as shopping, measuring distance, or time estimation. There are plenty of resources that provide real-life context, too, if you’re looking to save some time, such as my Garden of Rounding activity.
Not only do these activities make rounding more relevant, but they also help your kiddos understand why rounding is useful in everyday life! It’s always a win to prevent the question “when am I ever going to use this?“
5. Anchor Charts
As an avid reader of my blog, I’m sure you know by now just how much I love purposeful anchor charts in the upper elementary classroom! Anchor charts that outline the rules for rounding and provide examples can be a great reference tool. They can include visuals like number lines or rounding hills along with step-by-step instructions to guide students through the process. Anchor charts that show students what keywords to look for when estimating is also important!
Speaking of keywords, one valuable activity that I like to do is “To Round or Not to Round.” Students take a series of strips that they have read and sort them into columns determining if they can round the problem or if they need the exact answer for it. Sound helpful? I hope so, because I have this for you below FREE! Click on the image or click here to download it.
These tools and strategies are integral to help kids improve their number sense and rounding skills in the math classroom. Overall, each of these strategies are proven to make rounding numbers meaningful, engaging your students and building a strong foundation that will set them up for success throughout their scholarly career.
Try these ways to use visual models and diagrams for rounding in your math classroom this year! They’re sure to make your students more well-rounded. 😉