This learning resource is designed to help students master the concept of significant figures in measurements. It outlines the five key rules for counting significant figures: 1) Non-zero digits always count, 2) sandwich zeros between non-zero digits count, 3) leading zeros do not count, 4) trailing zeros count if there is a decimal point, and 5) trailing zeros do not count without a decimal point. The resource provides examples for each rule to clarify the concept. Students are then tasked with independent practice, counting significant figures in various measurements. Additionally, a practical application is presented where students measure dimensions using a digital caliper for a mission to study Mars samples, followed by a calculation of volume using the measurements. The importance of precision in significant figures during multiplication and rounding is emphasized, culminating in a final challenge related to the dimensions of a secondary battery pack that requires both calculation and appropriate rounding of significant figures.