Teaching adding and subtracting decimals can be a difficult task because it’s not necessarily the same process as regular addition and subtraction. There are many similarities because students still have to regroup as needed, but that decimal point can really trip students up. Today I’m going to share with you some of the ways that I teach addition and subtraction of decimals and some activities that I use with students to help them be successful through repeated practice.
Estimating Sums and Differences of Decimals
I like to help students figure out adding and subtracting decimals by estimating sums and differences of decimals. This will really help students to be able to notice if they’re close to the correct answer or if they’re way off track. We use guided math notes for estimating sums and differences of decimals as well as the standard way of adding and subtracting decimals. With these decimals guided math notes students will follow along while I complete a problem or two in front of them through modeling, work on two problems together with a partner and then work on two problems independently on their own.
Task Cards for Teaching Adding and Subtracting Decimals
After we go through the guided math notes I have students work through decimal task cards during their centers time to reinforce their learning and understanding. These task cards that I created go through the four operations of decimals, but I only give them addition when that’s what we have learned. Then I will add on each operation individually so they are only completing what they have been taught and should be starting to understand.
Scavenger Hunts for Teaching Adding and Subtracting Decimals
After students have had some practice with the decimal operations task cards, we go into a scavenger hunt style of review before moving on to multiplying and dividing decimals. With the decimal addition scavenger hunt, I will have students that are ready to really work independently go through the stations on their own since the activity is self-checking.
My students are able to work on their own and when they’re doing that I will pull a small group of students that could use additional support on the skill or even a prerequisite skill that they may not be as strong with. When students really have adding decimals down then we will do a decimal subtraction scavenger hunt so that they are able to practice that separately as well.
Real World Practice for Teaching Adding and Subtracting Decimals
To wrap up this part of our unit, we do some real world practice because I love to show students where they will be able to use our math concepts in real life. One way that I do this for teaching adding and subtracting decimals is using local ads. Students will be given a fake dollar amount that they can spend for a special occasion.
If it’s around Thanksgiving time in the United States where you are, you could give students a budget and have them create a meal within that budget. To extend the project further, you can have them look for coupons to save money and be able to add in something else that they would love to have in their meal.
Looking for more information about teaching decimals? Check out the blog posts linked below:
- 7 Tips for How to Teach Converting Decimals to Fractions
- Introducing Decimals to 4th Grade Students – Coming April 11, 2023