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Grade 2 · lesson 1 of 4

Measure When an Object Does Not Start at Zero

Locate the stated start and end marks.

About 15 minutes, plus any extended practice

Download the grade pack

Supplied materials

  • Paper and a pencil; drawing and spoken explanations are welcome. An adult may read directions and options aloud.
  • Supplied worked-case record: A strip starts at 2 cm and ends at 11 cm.
  • All quantities and shape descriptions are supplied in the worked example and questions; no purchase or personal information is needed.

Learn the idea

A ruler gives positions along a scale. If an object begins at a nonzero mark, its endpoint label is not its length. Count the intervals between start and end or subtract the two positions. Always report the supplied length unit.

Locate the stated start and end marks. Subtract start from end and check by counting the equal intervals between them. Explain why the end mark alone includes distance before the object began.

Count spaces between marks, not both endpoint labels. The end label equals length only when the start is zero. Draw a ruler segment and emphasize the two endpoints of the object.

  1. Draw a ruler segment and emphasize the two endpoints of the object.
  2. Follow the worked example. Point to each number or shape feature and say what it tells you.
  3. Locate the stated start and end marks.
  4. Try the question and then the three practice questions. Check your answers and explain any change you make.
Worked example

See the method in action

A strip starts at 2 cm and ends at 11 cm. Its length is 11−2=9 cm. Nine one-centimeter intervals lie under the strip. The endpoint eleven includes two centimeters before the strip’s start, so it is not the strip’s length. Count spaces between marks, not both endpoint labels. The end label equals length only when the start is zero. Draw a ruler segment and emphasize the two endpoints of the object.

Your turn

Check your reasoning

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Helpful tips
  • Count spaces between marks, not both endpoint labels.
  • The end label equals length only when the start is zero.
A strip begins at 2 cm and ends at 12 cm. What is its length in centimeters?

Feedback appears here after you check. This is practice, not a graded school assessment.

See the answer and explanation

10

Subtract the starting position from the ending position. The result is 10.

Take it further

Start 5 cm, end 18 cm. Expected: 13 cm.

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More practice: try new cases

Choose an answer for each problem. Explain your method on paper, then use the feedback to decide what to revisit.

More practice: try new cases
1. A strip begins at 3 cm and ends at 14 cm. What is its length in centimeters?
Need a hint?
  • Count spaces between marks, not both endpoint labels.
  • The end label equals length only when the start is zero.
2. A strip begins at 4 cm and ends at 16 cm. What is its length in centimeters?
Need a hint?
  • Count spaces between marks, not both endpoint labels.
  • The end label equals length only when the start is zero.
3. A strip begins at 5 cm and ends at 18 cm. What is its length in centimeters?
Need a hint?
  • Count spaces between marks, not both endpoint labels.
  • The end label equals length only when the start is zero.

Your choices are temporary. Feedback appears after you check all the answers.

Nothing here is saved to an account or sent to a teacher. Keep your own notes or download them before leaving. The score describes these questions; it does not certify subject mastery.

Check the subject sources

These LifeStarter passages, scenarios and exercises are authored for this Academy with AI assistance and review. External resources keep their publishers’ terms. A grade label suggests a starting level; it does not establish alignment with your school’s complete requirements.