In this unit, students discover that they can measure length using nonstandard objects that are smaller than the object being measured by counting how many of the nonstandard objects were used. Students experience measuring length using a nonstandard object (e.g. paper clip) as a measuring tool. Students learn that the paper clip, just like any other nonstandard object used for measuring, can be used to measure the length of a given object by iterating the paper clip to span the object from end to end with no gaps or overlaps. Students learn that the length of whatever they are measuring (e.g. the side of a textbook) is the length of however many nonstandard objects (e.g. paper clips) that it took to span the object from end to end.
Key Concepts:
 Lengths can be measured indirectly by iterating length units.
 The length measurement is the number of samesize length units that span it with no gaps or overlaps.
 Length measurements are only accurate if the end of the length unit and the object being measured are aligned.
Prior Knowledge Needed:
 Students can order and compare lengths (Ordering and comparing lengths; Grade 1, Unit 3; M.1.MD.A.1)
 Students can solve basic addition and subtraction problems; (Extending strategies for solving addition and subtraction problems; Grade 1, Unit 9; M.1.OA.A.1)
Units on the Horizon:
 Grade 2, Unit 02: Exploring standard units of lengths
 Grade 2, Unit 03: Relating addition and subtraction to length
 Grade 2, Unit 09: Generating and representing measurement data to solve problems
 Grade 2, Unit 14: Estimating and comparing lengths
Lessons

Lesson objective: Understand that length can be measured with nonstandard length units. Students bring prior knowledge of ordering three objects by length and comparing the lengths of two objects indirectly by using the third object from 1.MD.A.1. This...

Lesson objective: Measure length with nonstandard length units. This lesson helps to build fluency as students measure length with nonstandard length units. Different types of nonstandard length units are used in this lesson because it supports how m...

Lesson objective: Apply knowledge about measuring with length units to measure the length of items in the classroom. This lesson provides an opportunity for students to apply their knowledge and understanding of measuring with length units to a reallif...

Lesson objective: Extend understanding that length can be measured with nonstandard length units when the length units are the same size, when they have no gaps between them, and when they do not overlap. Students bring prior knowledge of measuring len...

Lesson objective: Measure length following the rules for measuring with length units. This lesson helps to build fluency with measuring with length units. The "Rules for Measuring Length" are used here because these rules support how to measure with len...

Lesson objective: Apply rules for measuring with length units to measure length accurately. This lesson provides an opportunity for students to apply their knowledge and understanding of the rules for measuring with length units to a mathematical situat...

Lesson objective: Extend understanding that length can be measured with nonstandard length units when length units are the samesize, when they have no gaps between them, when they do not overlap, and when they are aligned. Students bring prior knowled...

Lesson objective: Measure length following the rules for measuring with length units. This lesson helps to build fluency with measuring with length units. The "Rules for Measuring with Length Units" are used here because these rules support how to measu...

Lesson objective: Measure length with length units of the samesize that are aligned with no gaps and no overlaps. This lesson helps to build fluency with measuring accurately with length units. The "Rules for Measuring with Length Units" are used and r...

Lesson objective: Apply the rules for measuring with length units to measure length accurately. This lesson provides an opportunity for students to apply their knowledge and understanding of the rules for measuring with length units to a mathematical si...