Unit 4
Addition and Subtraction on the Number Line
Unit Goals
Unit Narrative
In this unit, students are introduced to the number line, an essential representation that will be used throughout students’ K–12 mathematical experience. They learn to use number lines to represent whole numbers, sums, and differences.
In a previous unit, students learned to measure length with rulers. Here, they see that the tick marks and numbers on the number line are like those on a ruler: both show equally spaced numbers that represent lengths from 0.
Students use this understanding of structure to locate and compare numbers on number lines and...
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