MAFS.1.MD.1.a Understand how to use a ruler to measure length to the nearest inch.

a. Recognize that the ruler is a tool that can be used to measure the attribute of length.

b. Understand the importance of the zero point and end point and that the length measure is the span between two points.

c. Recognize that the units marked on a ruler have equal length intervals and fit together with no gaps or overlaps. These equal interval distances can be counted to determine the overall length of an object.

Cognitive Complexity Level: 1-Recall

[divider] [/divider] Students are able to… 

  • Estimate the length of an object before measuring. 
  • Recognize a ruler is a model of equal (inch) units laid end-to-end, used to measure length. 
  • Use a ruler to measure length to the nearest inch.

[divider] [/divider] Students are able to…because teachers:

  • Require students to estimate and justify their estimation using benchmarks.
  • Relate the ruler to a number line to encourage understanding of length with equal iterations of a unit.
  • Pose opportunities for students to measure real world objects to the nearest inch with a ruler.
  • Guide students to create a ruler with inch square tiles to understand how a ruler works.

 [divider] [/divider] Questions to ask students:

  • Ask:  How do you know your object measures about 5 inches long?
    • Sample answer that indicates understanding: “Because the width of my thumb is about one inch wide and it took 5 of my thumbs to measure the length of the marker.”
  • Ask: What happens if you begin measuring an object at the 2 on the ruler instead of the 0?
    • Sample answer that indicates understanding:  “I need to count the number of units from the 2 to where it stops to find the length in inches.”
  • Ask: How does a ruler relate to a number line?
    • Sample answer that indicates understanding:  “They both have equal units.  The location where the object ends is the length of the object,  just like a point on a number line.”

 

[divider] [/divider] Additional Resources:

Additional in depth content knowledge

 

[divider] [/divider] Sample Formative Assessment Tasks:

Estimate the length of the toy car in inches.

Measure the length of the toy car in inches using your ruler.

How does your estimate compare to the actual length of the toy car?

[divider] [/divider] Resources/Tasks to Support Your Child at Home:

  • Math Task:  Using a ruler, have your child estimate the length of various objects in your home.  Then have them actually measure the length in inches.  Have them compare the estimate to the actual length in inches.