Subtraction With Regrouping

I’ll never forget the first time I was getting materials and lesson plans ready to teach addition with regrouping. I had moved from teaching first grade to second grade and had no idea what to expect. I’m sorry…. you mean we add and subtract above 20?! But WHY?! I finally got the addition stuff down and then it was time for subtraction. WHAT??? We just learned how to carry next door and now you want me to teach these little humans how to BORROW?! I really just needed someone to give me a coke and tell me everything would turn out fine!

It was that year that I knew I had to step up my game in the math department. We needed more than worksheets and workbooks. I spent that year focused on creating engaging ways to present new material to my students…. and that was 10 years… ago before Pinterest, Instagram, and the such. Now I feel like a have a HUGE toolbox full of math ideas, lessons, and activities to share with students and teachers! So, let’s begin. Let’s take a look at a few activities and lessons that can be used to lighten that regrouping load a little!

Please Note: All of the lessons and activities in this blog post come from THIS unit. I also have a FREEBIE for you within the post!

Build Numbers to Subtract

During the lesson, building numbers is crucial. Regrouping is such an abstract concept that manipulating the numbers makes it more concrete for our students. Here’s a little breakdown of how to build a subtraction with regrouping problem:

1. Build the total using tens and ones blocks. I built the number 73 with 7 tens and 3 ones.
2. Look at the number you must subtract from the total. Go to the ones place. I need to take away 9 ones, but I only have 3 ones. I went over to my tens place and I borrowed a ten. I physically moved that ten into my ones place.
3. In order for me to manipulate the number better, I must trade out my ten for 10 ones (after all, a tens block doesn’t belong in the home of my ones!). So, I place 10 ones in the bottom half of the board. Now I have 13 ones and 6 tens.
4. Now that I have 13 ones I can take 9 ones away. I remove those ones. I have 6 tens and I need to take away 2 tens. I remove the tens.
5. Now I can see that my answer is 44!

When introducing for the first time, go very very slowly. This is not a sprint, it’s a marathon… one that needs to be revisited often!

Here’s a little video to explain it step by step:

Subtraction Rhyme

Once the students understand HOW to subtract, they must learn how to IDENTIFY when regrouping is necessary. That’s when this subtraction chant comes in handy:

SUBTRACTION WITH REGROUPING: More on the floor? Borrow from next door!

SUBTRACTION WITHOUT REGROUPING: More on top? No need to stop!

ONES PLACE HAS THE SAME NUMBERS: Numbers the same? Zero’s the game!

Repeating this chant often helps to engrain it into the students’ memory. Not every problem is exactly the same, so the chant helps them to remember to pay close attention to that ones place.

Subtraction Games

Eventually students will get to play games so that they can practice, practice, practice regrouping in a fun and engaging way. Here’s how to play this game:

Flip it! Draw it! Solve it!

1. Students flip over four numbers (must arrange the numbers appropriately).
2. Students arrange to create a subtraction problem.
3. Students draw base ten blocks to solve.

Interactive Notebooks

When it comes to independent work, I still try to make it as interesting as possible. Interactive notebooks come in handy in a HUGE way. Here’s how Mixed Up Subtraction Snowmen works (You’ll get this as a FREEBIE below):

1. Students have two numbers on the snowman, but they may not be arranged in the correct order to subtract.
2. Students find the greatest number to become their total.
3. Students then subtract the other number from the total.
4. Students solve their problems underneath the snowmen.

A Memorable Moment

Of course I’m always looking for a way to make those memorable moments… even if we are just doing subtraction with regrouping. That’s where The Minus Man comes in! The Minus Man wants to eat subtraction problems, but the students must create those problems first! Students spin numbers to create their problems. BEFORE The Minus Man eats the problems, the students have one last job! They have to order the answers from least to greatest. Then the students can glue their subtraction problems inside of The Minus Man.

A FREEBIE for you!

Don’t want to forget these math lessons and activities? Pin the image below to your Pinterest boards!