Do you teach your students the traditional method (or standard algorithm) of adding and subtracting decimals? The standard algorithm is important and I usually don’t have a lot of trouble getting my students to master this, but do our students truly understand what they’re adding and subtracting? Do they have a strong foundation and understanding of decimals and their values?
When I introduce adding and subtracting decimals, I teach the visual model in conjunction with the standard algorithm. My students see what the decimal looks like when it’s represented in a hundredths grid as part of a whole.
Here’s my process:
- I begin with guided notes that have step-by-step instructions and graphics on how to create a visual model as well as the standard algorithm.
- We go through an example problem together and I have a student demonstrate by annotating over the notes page on the Promethean Board while the others fill theirs in within their composition book.
- Students then work independently creating visual models for adding and subtracting decimals, solving each of the problems using the standard algorithm, and comparing their answers from both strategies to make sure they match.
- After students have begun to show mastery over a few days, I have them work with a partner using our Task Tents™ review activity.
- I assess their understanding with a quiz.
I have a resource that gives you everything you need. You get an introduction, guided practice, independent practice, Task Tents™ for review, and an assessment.
Click here to start using visual models for adding and subtracting decimals with your students.