CKMath Unit 5: Multiplicative Comparison and Measurement
Focus:
In this unit, students make sense of multiplication as a way to compare quantities. They use this understanding to solve problems about measurement. In earlier grades, students related two quantities and made additive comparison, where the key question was “How many more?” Here, they make multiplicative comparison, in which the underlying question is “How many times as many?” For example, if Mai has 3 cubes and Tyler has 18 cubes, we can say that Tyler has 6 times as many cubes as Mai does. Initially, students reason using concrete manipulatives and discrete images. Later, they reason more abstractly, using tape diagrams and equations. Comparative language such as “_____ times as many (or much) as ____” is emphasized, offering students opportunities to attend to precision as they communicate mathematically. Next, students use the idea and language of multiplicative relationships to learn about various units of length, mass, capacity, and time, and to convert from larger units to smaller units within the same system of measurement. For example, they describe 1 kilometer as 1,000 times as long as a meter. Students then use their new knowledge to solve measurement problems.
Number of Lessons: 17 and 1 optional
Instruction Time:
Approximately 60 minutes
(Please note that each lesson is designed for one instructional block, and may be divided into shorter or longer segments based on teacher pacing and student needs.)
