In middle school, a fundamental understanding of the basics of stoichiometry can help lay the foundation for chemistry in later years. When I teach stoichiometry basics in my middle school classroom, I start with very basic chemical formulas and incremental increase the complexity as students achieve and demonstrate mastery at each level. I use task cards for reinforcement.
How many atoms are there?
Given a chemical formula, students need to be able to identify how many atoms there are of each type. For example, in H2O, there are 2 hydrogen atoms and 1 oxygen atom. I use drag and drop Google Slides task cards that break the process down into several tiers. First, I teach basic subscripts.
The key here is to practice this skill until it is mastered before you introduce coefficients, which is the next step.
Again, the key is to practice this skill to mastery before complicating things. For some students, this may be the most advanced stoichiometry they can master at this time. For others, you can add parentheses.
Practice until mastery and then advance your students to parentheses with coefficients.
In all, advancing through these stages of basic stoichiometry may take your middle schoolers several days, but they they are ready for balancing equations.
Just like in basic stoichiometry, student mastery of balancing equations comes with guided practice in incremental steps. Start with a few simple synthesis or decomposition reactions with only 2 elements.
For some students, this may be quite challenging in middle school, depending of course on their pre-algebra skills. If your students are asking for more complicated problems, try a single replacement reaction.
Again, they key is mastery at each incremental step before advancing to a more complicated type of problem.
This is why large task card sets are so important when you’re teaching basic stoichiometry in middle school. Lots of practice leads to increased understanding and retention.
I offer several basic stoichiometry task card sets in various formats in my TpT store if you want more guidance: