2nd-Grade Math Assignment

Focus
This assignment is partially aligned with second-grade standard 2.MD.A.1, which requires students to select and use various standard tools such as meter sticks to measure length. In this assignment, students use a centimeter ruler to measure the length of several objects. Measuring length in centimeters with a ruler is appropriate, but students didn’t get to select the most appropriate tool to use given the objects being measured. This is a key aspect of 2.MD.A.1, because part of measurement proficiency is understanding that unit size matters and that it’s more efficient to measure objects of different sizes with different units. For example, centimeters are appropriate when measuring the length of a paper clip, while meters are better suited for measuring the length of a room. 

Rigor
This assignment builds students’ procedural skill, the aspect of rigor outlined in standard 2.MD.A.1. Students have multiple opportunities to practice using a concrete tool (centimeter ruler) to measure length. Students must use the tool correctly (for example, aligning the edge of the object at the zero mark on the ruler) to accurately complete the problems. 

Practice Standards
This assignment gives students a chance to superficially engage with Mathematical Practice Standard #5 ("Use appropriate tools strategically"). Students repeatedly practice using the tool of a centimeter ruler to measure length but aren’t required to select the most appropriate tool to use given the objects to be measured. Selecting the most appropriate tool would give students a meaningful opportunity to engage with the practice standard.