One area that I see often when I'm observing in classrooms is that teachers go from a visual representation of something straight to the abstract. There needs to be other pieces in between these two steps where students have opportunities to make meaning with the manipulatives and have scaffolded opportunities to move from the concrete to abstract. In order to do this there are several steps to think about.
1. Student exploration with materials and attempting to solve the subtraction problems. Here is a student using paperclips to explore measurement.
2. Teaching with visuals and manipulatives to solidify the student exploration, clarify misunderstandings, or directly teach a brand new concept. Also, this doesn't just mean one form of manipulatives.
3. Highlight specific content words that will be necessary for explaining the process of subtraction. This would include difference, subtraction, etc.
3. Student talk about subtraction. In order to understand the concept, students need to be able to display their thinking visually and talk or write about it using the specific content vocabulary from #3. This needs to be both teacher supported and collaboratively with peers.
4. Once these pieces are in place, then I think it's appropriate to move to the abstract or formula-based solving of subtraction.
And finally, students need to have FUN with subtraction! Once there is a conceptional understanding, games are a blast to play, and they make subtraction a little less stressful for students. Here are some really easy games to print and play that I've created for subtraction.
This is the easiest version with just basic subtraction facts. Use this game as a small group review game or to practice fact fluency add a timer to the game! On TpT for $1.00!
This game includes double digit problems with regrouping. This is definitely one of my best-sellers - it's only $1.50! Use this as a whole class review game with students using dry erase boards at their seats to solve all of the problems. A great class game or to use when you have a substitute teacher.
This game has 2-digit problems with and without regrouping. Put this at a work station for students to solve and put the cards in order based on the answers they get when solving each problem. A great way to encourage practice through a fun game! Again, just $1.50!
Happy subtraction to all! Gotta run, err continue to walk post-baby for a while!