Length estimates & problems

Follow a length story

Join, cut and compare lengths, including a missing starting amount.

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8 practice questions · Optional read aloud · Thinking pad

Let’s understand the idea.

  1. Name each length and find exactly what the question asks. All the lengths in these stories use the same unit.
  2. Join parts to find a total. Find a difference for a cut, an extra length or a missing part.
  3. Sometimes you know the ending length. Put a removed part back to find the starting length, and check the story in order.

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.

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Curriculum connection

Grade 2 · 2.MD · US Common Core

2.MD.B.5

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.

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