A number is a distance from zero
Represent whole numbers and addition or subtraction with equally spaced points.
Explore this lesson →8 practice questions · Optional read aloud · Thinking pad
Let’s understand the idea.
- Every step between neighboring whole numbers has the same length. A number names a point and its distance from zero.
- Addition moves right and subtraction moves left. A change of zero keeps the same point.
- Split a change into tens and ones if that helps. Keep each jump's distance true to its amount.
Something to notice
Ask the learner to estimate before measuring real objects, compare measured lengths in the same units, and explain which relationship fits a length story. Estimates depend on the reference and need not be exact. These multiple-choice estimates select the best of the supplied alternatives; they do not grade every possible spoken estimate. Observe independently created number-line drawings and explanations. The scaled diagrams are not actual-size measuring tools.
Try it. Change it. Explain it.
Open the lesson to use its pictures and controls. In How it works, connect the picture to the idea. In Play & discover, change the quantities and notice what stays the same. In Your turn, answer questions and use the explanation to check your reasoning.
You can ask for help, draw on the thinking pad, or listen to the question and answer options. Progress distinguishes independent work from work completed with help.
Let’s try it →Curriculum connection
Grade 2 · 2.MD · US Common Core
This lesson is mapped to these standards. A completed activity is practice evidence, not a claim of mastery. Content is checked against the linked official standards and its mathematical models are tested.