If you are teaching addition and subtraction with regrouping in your classroom you have an opportunity to build number sense at the same time through the activities that you use!

Let’s first stop to acknowledge that addition and subtraction with regrouping using the standard algorithm is not a 2nd grade standard even though the skill is often taught in second grade! If you are a second grade teacher, the algorithm is absolutely NOT a must!

We can use addition and subtraction with regrouping activities to BOOST our students’ number sense!

How can we build number sense? We can build our student’s flexibility with numbers by strengthening their understanding of number relationships including:

- One More/One less and Two More/Two Less
- Spatial Relationships
- Part/Whole Thinking
- Benchmarks Numbers

Each of the following fraction addition and subtraction with regrouping activities will target and boost one (or more!) of these number relationships for your students.

**This is certainly not an exhaustive list of addition and subtraction with regrouping activities but rather a look at a few easy-to-implement activities through the lens of number sense**.

## Master the Basics FIRST!

Before you jump into addition and subtraction with regrouping activities, be sure that your students have mastered the basics.

Your students will better be able to assess the reasonableness of their responses to an addition or subtraction question if they have number sense around 3- digit numbers.

Try this! Ask your students to build a 3-digit number using base ten blocks (or place value disks, or whatever tool you have on hand!). Then, ask them to find 1 more, 10 more, 100 more or 1 less, 10 less or 100 less.

This will boost your students’ **1 more/1 less **relationship with groups of 1, 10 or 100! Additionally, using a hands-on tool will build your students **spatial relationships **as they see the difference in their model when they adjust a number by 1, 10 or 100!

## Start with Groupable Models

When you first teach addition and subtraction with regrouping, don’t jump straight to base ten blocks!

Instead, start with a groupable model such as linking cubes, bundles of straws or cups of small objects like beans or mini erasers.

Why?

When we ask our students to add (or subtract!) with a groupable model our students physically see a ten being composed or decomposed to add or subtract.

This will boost your students’ **spatial relationships **of addition and subtraction when it comes to regrouping!

When your students can visualize the act of composing a ten or decomposing they better understand the operation!

## Place Value Charts Aren’t Only For Numbers!

When your students are ready to pair their hands-on materials with a written method, don’t skip over representational models!

Asking your students to draw small circles or dots on a place value chart to represent their addition or subtraction equation can boost your students’ understanding of the algorithm AND your students’ number sense as well!

If your student is to represent the equation 357 + 146 for example they would represent 3 dots in the hundreds column, 5 dots in the tens column and 7 dots in the ones column followed by 1 dot in the hundreds column, 4 dots in the tens column and 6 dots in the ones column. Your students can then add to find the total number of ones, tens and hundreds regrouping as necessary.

This BOOSTS your students’ **benchmark of 10** as your students look at the 5 groups to quickly note whether or not a new group is made.

This also BOOSTS your students’ part/whole relationship as they are essentially decomposing each addend into hundreds, tens, and ones before adding or subtracting. Students are creating a visualization of 3-digit numbers in expanded form.

## Related Resources

Looking for activities to support your small groups in understanding fraction comparisons? Check out these addition and subtraction units! They include everything you need to teach the concept including:

- Simple to implement ENGAGING lessons
- Pre and Post Assessment
- Independent Practice Activities
- Daily Exit Tickets for Understanding

Units are EASY to prep, EASY to follow and pack a punch in terms of helping your students to understand difficult concepts such as comparing fractions!

### Teachers Who Have Used These Units Are Saying:

- “I love these for small groups! So nicely planned and the students find it so fun!” ⭐⭐⭐⭐⭐
- “Love this resource, It has really helped me in the classroom!” ⭐⭐⭐⭐⭐
- “I used this with a few of my students who were struggling with our previous subtraction lessons in class. My students were fully engaged in these lessons and I loved how easy they were for me to follow.” ⭐⭐⭐⭐⭐