Understanding and calculating using significant figures (or significant digits) is one of the fundamental skills of Chemistry and Physics. The concepts of accuracy, precision, uncertainty, and error in measurements and calculations can be challenging for students, especially when encountering them for the first time. These are the kind of skills that need to be actively practiced, and not just passively studied from a distance. When students have the opportunity to use their new skills repeatedly, along with teacher feedback, they are more likely to internalize their understanding of the rules and process.
I use this worksheet in class to give my students more practice with the rules of rounding with significant figures. The front side includes mixed addition and subtraction problems, while the back side covers multiplication and division.