The document is meant to act as a resource for elementary through middle school teachers, featuring 6 science activities connected to Indiana state standards with grade-appropriate science connections aimed toward 5th, 6th, 7th, and 8th grade.
The entire point of this piece is simply to introduce balancing charges in ionic compounds. This is a simpler method to get students thinking about the idea, which also makes it suitable for pre-high school students. It gives a visual representation of how charges balance and how cations pair with anions. At this level, it is very similar to least common denominator calculations.
Stan, Patricia L. and Knight, Emily, "Educational Resources: Ionic Matching" (2018). Collaborative Scholarship: Chemistry. 2.