One of the most dreaded units in first grade (and sometimes second grade) is addition with regrouping! When I was a little girl many moons ago (ha!) we were simply told, “You carry the one.” That’s it. No explanation, no rhyme, and no reason. I really didn’t know *WHY* in the world I was “carrying” that number over. I just did it so my teacher would be happy! (Little people pleaser back then, too. 😉 )
But gone are the days of saying “just do it.” (Unless you’re Nike, of course!) Now we want to be sure students understand the whats, the hows, and the whys. That’s what I love about the CPA math model. It moves from Concrete Experiences (using math tools and manipulatives) to Pictorial Experiences (using images and drawings) to Abstract Experiences (using numerals and symbols like + – x / ).
As I prepare to teach my firsties (who just mastered two digit addition without regrouping using the activities from this unit) two digit addition WITH regrouping, I wanted to be sure and research best practices and follow the CPA model again. They were so successful following this model before. Following are some activities that will help you teach your own students two digit addition with regrouping. And I’m going to let you in on a little secret. These activities are FUN y’all. Like, they’ll beg to do them….again and again!
We start with concrete experiences…using manipulatives. I prefer linking cubes to begin (as opposed to base ten blocks) so students can actually build the tens by linking ten ones together. After they have FULLY grasped this concept, they can move on to base ten blocks–including paper ones! Race to 100 (or Race to 50) is a fun game. As students roll two dice and add them together, they count out ones cubes and place them in a ten frame. Then, they roll again. Again, they count out ones cubes, filling up any remaining spaces in the ten frame before moving on. But wow…they’ll notice that the entire ten frame is now full. This is your chance to introduce the term “regroup” by telling them to bundle those ten ones into a group of one ten. And move that new ten over into the tens column. They have officially regrouped the ones into a ten. Play proceeds, trading ten ones for one ten, until the students have accumulated ten tens. Have them count each bundle by tens and they quickly realize they have now reached 100! Game over!
Next, I introduce adding two digit numbers and regrouping using a double place value mat. Students build their first addend (tens and ones) using base ten blocks on the top half of the mat. Then they build the second addend (tens and ones) using base ten blocks on the bottom half of the mat.
Then have students slide the ones together by filling up the ten frame at the top first and then filling in any remaining places in the ten frame at the bottom. Next, have them slide the tens trains all together. They’ll notice that there are now ten ones plus a few extras, so remind them to “regroup” by trading those ones for a ten. Now they’ll place the ten in the tens column and count how many tens in all and how many ones in all. This makes a great center using the recording page provided.
Another fun way to practice place value and addition with regrouping is by using alternative manipulatives. Use pretzel rods and mini marshmallows or craft sticks and pom poms for tens and ones. I love getting seasonal paper straws and cutting them apart to use for my tens rods. Be creative!
For the next series of lessons, I capitalize on students’ knowledge of expanded form–which we have practiced and practiced ALL.YEAR.LONG.
We use an Addition Tree Work Mat–with many, many branches–to add two 2-digit numbers. Essentially, we’re breaking down both of our original addends into the simplest expanded form we can come up with. This is more of a Common Core approach to two digit addition so if your school doesn’t teach CCSS you don’t have to use this approach. Even though our school is NOT a CCSS school, I think this visual is very helpful for many of my little learners. So, I choose to add a few days for us to work on this method! Again, this makes a great center. I love these write and wipe pouches from Learning Resources (affiliate link). Instead of laminating, you can place pages in these pouches making the pages reusable and perfect for centers!
Did you know that you can actually PRINT from your copier or printer on Post It Notes? YES!! You’ll print out the template I provide, add Post It Notes to cover each square and then be sure you feed them into the printer correctly. I experimented with a plain white piece of paper first to see which way I needed to feed it into the printer so the Post It Notes didn’t peel off and jam the printer!
I instruct students to add the ones first. Again, this is something I have DRILLED AND DRILLED AND DRILLED. (I even hear “Start on the right with the ones!” in my sleep all the time! ha!)
We write that sum on a sticky note. But….uh oh! We can’t fit two digits in the ones place!!! Each place in the place value chart will only hold one numeral.
What’s a kid to do? Why, perform surgery, of course! Students grab their scalpel (er…scissors) and cut those two numbers apart.
Then we chant, “The tens go UPPPP and the ones come DOWNNNN.” And we *really* dramatize “up” by making our voices go UP and “down” by making our voices go down deep. We stick the tens side of the sticky note UPPPPPP in the top of the tens column. And we stick the ones portion of the sticky note DOWNNNNN at the bottom of the ones column. Then, we continue by adding the 3 addends in the tens place. (The students have already mastered adding 3 addends using the activities in this unit.) I cannot tell you how game-changing this trick is for teaching your littles how to regroup using the traditional algorithm minus place value blocks. CRUCIAL!
This may just be the light-bulb moment of your entire teaching career! 🙂
And this little craft just “SUMS” it all up. <— See what I did there??
NOW we can move on to the more traditional algorithm after students have had LOTS Of practice with this method. I like to use a special grid with my firsties in the beginning to help them keep the tens and ones lined up. It includes a special box above the tens column for them to use in regrouping. This makes a fabulous center once students have built independence with this method. I like to mix up my presentation of horizontal and vertical equations because it’s critical for students to be able to go back and forth between the two while properly aligning the tens and ones.
Students continue to progress toward more and more abstract opportunities to add with regrouping using numbers and symbols instead of manipulatives or pictures. The final step in the process is reminding students that not *every* equation will require regrouping! So, it’s important to give them some clear-cut rules to remember WHEN to regroup.
What tricks do you have up your sleeve for teaching addition with regrouping? This packet is great for not only introducing the concept to first or second graders…but also for remediation for older students or students with learning disabilities who just aren’t getting it!
You can find all of the games and resources mentioned above….plus MUCH more….by clicking below!
Be sure to pin this post so you can find these ideas again!