Comparing Measurements with Different Units

Khan Academy

This educational video guides students through the concept of measuring length using different units. Through a digital interface, the narrator demonstrates how to measure various colored lines using both non-standard units (colored rectangles) and a standard centimeter ruler. The video explicitly compares the results of these two measurement methods to help students understand the relationship between the size of a unit and the number of units required to measure an object. The content focuses on three distinct examples where lines are measured simultaneously with rectangles and centimeters. In each case, the narrator highlights that when a measuring unit is larger (like the rectangle), it takes fewer of them to cover the length of the line compared to a smaller unit (like the centimeter). This repetition reinforces the inverse relationship between unit size and measurement count. For educators, this video serves as an excellent tool for bridging the gap between non-standard and standard measurement in early elementary math. It visualizes the abstract concept that "bigger units mean smaller numbers," providing a concrete foundation for understanding why standardized units are necessary and how they function. The interactive-style walkthrough makes it easy to replicate similar activities in the classroom with physical manipulatives.