If your grade level has standards around rounding numbers then you have thought long and hard about how to teach rounding to students who are struggling with math. There are two main schools of thought here.
- Teach the students HOW to round. This may include a rhyme, an anchor chart, or another method that teaches a procedure that, when applied correctly, will result in rounded numbers.
- Use conceptually based methods such as a number line.
The thing is, rounding is actually a very simple skill. Students who struggle to round numbers most often don’t have a misconception about how to round. They lack an internal number line, understanding of place value, and the number sense that allows them to be able to round.
I implore you to choose option #2.
How To Teach Rounding Through Number Sense Activities
The thing is, rounding is actually a very simple skill. Students who struggle to round numbers most often don’t have a misconception about how to round. They lack an internal number line, understanding of place value, and the number sense that allows them to be able to round.
In other words, it’s not a rounding issue. It’s a place value and number sense issue.
To teach learners who are struggling to round, spend the majority of your time developing number sense and place value understanding and your students will pick up the skill of rounding quickly as a related afterthought.
Two main activities you will want to focus on include:
- Identifying benchmark “round” numbers when counting by 10, 100, 1,000, tenths or whatever you may be rounding to.
- Knowing how to count between these benchmark numbers.
Activities for Identifying Benchmark Numbers
- Play round robin skip counting games like “Buzz”. Students stand in a circle and you will identify a start number (ex: 250) and a buzz number (ex: 430). Starting with the start number students will count round robin from the start number to the buzz number. Whoever says the buzz number sits down and the game continues.
- Play “Find the Hidden Number” by giving students a number line counting by a particular interval (ex: 100, 200, 300, etc.) Ask students to point to the number line to find the spot where numbers are “hiding” (ex: Where is 438 hiding?)
- Play “Missing Number”. Draw an open number line on a whiteboard. Label the number line with benchmark numbers (ex: 0, 10, 20, 30, 40, etc.) Ask your students to close their eyes as you erase one number from the number line. Say “Find my missing number” to your students as a cue to uncover their eyes. Their job is to call out the missing number as quickly as possible.
Activities for Counting Between Numbers
- Write the numbers between two benchmarks on post-it notes. Post the benchmark numbers on a classroom whiteboard and draw a number line between the two numbers. Give students the remaining post-it notes and ask them, one at a time, to determine the spot where they think their number would go. (ex: 4,500 to 4,600. Post-it notes include 4,510/4,520/4,530, etc).
- Repeat the same activity, however, rather than using post-it notes, give students their own whiteboard and ask them to write in the numbers between two benchmarks.
- Option 1: Ask your students to write all of the numbers at once. This would likely be more familiar or a more simple version of this activity.
- Option 2: Ask your students to plot specific numbers in your chosen order (Ex: Write an open number line from 100 to 200. Where would the number 140 be placed on your number line?) You can increase support by asking your students to place the midpoint (150 in this case) first and then following with numbers that are nearby to the benchmarks (ex: 150, 110, 190, 140, 160…) and can increase difficulty by providing your students with numbers in an order where they aren’t necessarily close to one another (140, 180, 160, 130, etc.)
How to Transition from Number Sense Activities to Rounding
If your students are fluent in counting by and knowing benchmark numbers and they also have an internal number line that lets them know where a number falls between two benchmarks, rounding is really a simple skill! You can scaffold this by thinking CRA.
- Give a student post-it notes with benchmark numbers and the numbers that come between them (ex: 20 & 30 in one color and 21, 22, 23, 24, 25, 26, 27, 28, 29 in another) and ask your students to identify numbers that are closer to one benchmark or the other.
- Ask students to draw an open number line on a whiteboard and to round a number to the nearest benchmark by marking out the benchmark numbers and the midpoint.
Remember, if you think you have a rounding problem, you likely have a number sense problem instead! Shore up your students’ number sense and you will serve them far beyond the skill of rounding!
Related Resources For How To Teach Rounding
Rounding To The Nearest 10 and 100 Without Rhymes
“I’ve never felt compelled before to finish teaching a product and then run to give it positive feedback right afterward, but here I am. I co-teach an inclusion math class and we’ve tried every trick in the book for rounding… but now our kids actually UNDERSTAND it! Almost every hand shot up, and even when I showed them a bonus “now let’s zoom into a number in the hundreds place,” they knew it, without me having to explain anything! I will use this every year moving forward. My co-teacher, on the way out the door, said, “That was EXCELLENT.” Where have you been all our lives? lol Thank you!! I don’t think I despise rounding anymore!”
Rounding Decimals Lessons & Activity
“This helped my students that were struggling with the concept of rounding decimals. I was able to use it multiple times in small groups to solidify their understanding. Thank you so much!”
“I used this to help students conceptually understand decimals because using the song is not enough. Thank you for this!”
