Domain

Measurement and Data

Cluster

Measure and estimate lengths in standard units

Standard(s)

NC.2.MD.1 Measure the length of an object in standard units by selecting and using appropriate tools such as rulers, yardsticks, meter sticks, and measuring tapes.

Materials

String measuring 8 inches in length, ruler, yardstick, meter stick, measuring tape

Task

Show the student the materials.  Say: I have a piece of string.  What tool do you think we should use to measure the length of the string? 

After the student selects a tool ask: Why did you choose that tool? 

After the student provides and explanation, say: Use your tool to measure how long the string is.  How long is the string?

Continuum of Understanding

Not Yet Proficient

Needs prerequisite concepts

Selects the correct tool and measures accurately:

❑    Selects the ruler

❑    Uses the ruler correctly, lining up the end of the string with the zero point on the ruler.

Progressing

·      Does not select a ruler.

·      Selects a ruler but doesn’t provide a reasonable explanation.

·      Inaccurately measures the length of the string.

Meets Expectation

·      Selects a ruler.

·      Explanation includes an understanding that the string is a relatively short object and a ruler is an appropriate tool for shorter measurements (may state that all of the tools could be used to measure the string).

·      Measures the length of the string accurately, aligning the starting point of the ruler with the end of the string.

·      States that the string is 8 inches in length.