Teaching subtraction with regrouping using the standard algorithm? You’re in the right spot! But, if you are teaching 1st or 2nd grade, please remember, the written algorithm for addition and subtraction isn’t necessarily the end goal!
Your students need to use strategies based on place value and relate them to the written strategy. Can the standard algorithm be the written strategy you are relating their place value thinking to? Sure thing! But if your first or second grade students continue to need hands-on materials or representative drawings – don’t stress! They are exactly where they need to be.
Those caviats aside, let’s talk about how we can move students from hands-on to a written method!
1. Start With A Groupable Model
Start with a groupable model such as linking cubes. Bundles of straws also work fantastically! You want to use a tool that will allow your students to literally unbundle a group of ten into ten ones if needed.
Using these tools on top of a place value chart helps to keep work neat, organized and lends itself to a written model down the line.
2. Move To A Pre Grouped Model
3. Link To A Written Method
4. Move To A Representative Drawing
When your students are consistently successful modeling subtraction using hands-on tools, consider moving to a representative model such as drawings on a place value chart. This is an intermediate step that will support your students in moving from concrete (hands-on) to abstract (the written method).
For example “We had 8 ones and took 6 ones away using place value disks. What would it look like if we took 6 away from a place value drawing? Let’s show that on our white boards!”
5. Link To A Written Method (Again)
That’s it! Now, follow these steps yourself or grab my ready-made unit. You will find pre and post assessment, five lessons (hint- they follow these five steps!), independent practice to mirror each lesson and exit tickets so you can progress monitor along the way!