Regrouping Fun with Two Digit Numbers

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Double digit addition with regrouping is another tricky concept for children to learn and understand.

There are different methods for teaching addition with regrouping and one way is with math manipulatives. I prefer to use MAB blocks (place value blocks) but unifix cubes work well too.

But before I even begin to teach the concept my students need to have a very sound understanding of place value and how to decompose numbers into tens and ones. They really need to know that fifteen is fifteen ones and also one ten and five ones if they are going to understand why we regroup.

Using Manipulatives to teach addition with regrouping

To introduce regrouping I have a tens and ones chart for every child. I must admit mine are not very flash. The kids themselves fold a piece of card in half and write tens on one side and ones on the other.

Then we practice making a two digit number by placing our ones in the ones column and our tens in the tens column. Underneath that we make another two digit number and then we add.

Always add the ones first. This part doesn’t come naturally because it contradicts the way that numbers are read (left to right) and kids will generally want to add the tens first. So right at the very beginning of double digit addition, even before we introduce regrouping, we need to reinforce this concept.

We push the ones together; 7 and 9 makes 16. Do we have enough ones to make a ten? (This is why kids need to have a good knowledge of tens and ones.) Yes we do. We trade 10 ones for a ten. Can we leave it in the ones column? No we can’t. We put it in the tens column. Now we have 3 tens and 4 tens + 1 more ten. We push them together and look at our answer – how many tens, how many ones? What’s our answer? 37+49 = 86.

Once my kids understand this stage we move onto modeling and writing the equation.

Once the concept is understood we can put away the MABs and just write the equations. This is when I love to bring out the games.

Practicing addition with regrouping using games

Let’s face it, writing pages of equations is boring but writing equations in order to win a game is not.

Kids can write down the equation they land on and find the answer on the game board.

Or spin two numbers, add them and move their game marker to that answer.

After recording the equation in their notepads or on a recording sheet (provided in this game pack), students need to use their knowledge of place value to determine where the answer will fall when they use this game.