Student Actions

Teacher Actions

• Develop strategies for problem solving by choosing the appropriate measurement tool for the task, recognizing that the size and nature of the object to be measured should be considered (i.e., a ruler or yardstick will work well for a window or door, but a measuring tape works better for the edge of a curved table).

• Develop accurate and appropriate procedural fluency by measuring the length of a wide variety of objects, using various tools.

• Develop a deep and flexible conceptual understanding of measurement to a fraction of an inch by identifying half-inches and whole inches as appropriate expressions of ‘nearest quarter-inch.’

• Implement tasks that promote reasoning and problem solving by providing a wide variety of real-world objects which can be measured by students, as well as various measurement tools for students to use.

• Use and connect mathematical representations by linking students’ understanding of fraction equivalence to tasks requiring measurement to the nearest quarter-inch.

• Support productive struggle in learning mathematics by providing tasks which require the student to find an accurate measurement without starting at ‘0’ (i.e., measuring with a ‘broken ruler’).

Key Understandings

Misconceptions

• There is an appropriate measurement tool for  each object being measured. 

• A variety of tools can be used to find accurate measurements, with precision of measurement to the nearest whole centimeter or nearest quarter-inch.

• There are two measurement systems: metric and customary. They can both be used to measure length but the units of measurement are different.

• It is appropriate to begin measuring at the end of the ruler, instead of at the zero.

• It is wrong to measure by starting at any point on the ruler other than zero.

• It is appropriate to count the lines on the measurement tool, rather than the spaces between the lines.

• The measurement tool must be longer than the object to be measured.  

• Meters and yards are equivalent.