General Information
Subject Area: Mathematics (B.E.S.T.)
Grade: 2
Strand: Measurement
Date Adopted or Revised: 08/20
Status: State Board Approved
Benchmark Instructional Guide
Connecting Benchmarks/Horizontal Alignment
Terms from the K-12 Glossary
- NA
Vertical Alignment
Previous Benchmarks
Next Benchmarks
Purpose and Instructional Strategies
The purpose of this benchmark is to build instruction from grade 1 to include additional U.S. customary and metric units. Students will both estimate and measure objects in various units and are expected to select an appropriate measurement tool.- Instruction includes helping students identify benchmark measurement references.
- Instruction includes helping students connect the concept of a number line to linear measurement tools such as rulers and tape measures.
Common Misconceptions or Errors
- Students may misalign the ruler with the object and measure an object from 1 instead of 0.
- Students may count all marks, not just the whole-unit marks, when labeling a ruler.
- Students may not have a clear concept of the approximate length of an inch, a foot, a centimeter or a meter.
Strategies to Support Tiered Instruction
- Instruction includes modeling how to measure an object and guiding students to notice that the object’s measurement does not change if the object is placed further down the ruler.
- For example, modeling may include identifying the end points of an object and lining the end point with the zero mark of the ruler. Note that often the “zero” mark is not labeled and may be the end of the ruler or on the very first tick mark depending on the ruler. The teacher states the correct measurement and then as students watch, move the object down the ruler and ask, “Does the object’s measurement change if its end point lines up with a different number?”
- Instruction includes directing students to make connections between their world and measurements of inch, foot, centimeter and meter. Students discuss these relationships, draw pictures and write labels that can be used as a reference to help them remember the different length units and their approximate sizes.
- For example, students can use index cards to draw examples of each length unit relationship. Multiple cards can be made so that students can sort, do a memory match, or combined to create a mini booklet.
Instructional Tasks
Instructional Task 1 (MTR.4.1, MTR.6.1)
As a class, determine several classroom objects whose lengths can be measured (e.g., pencil, book, desk, glue stick, etc.).- Part A. Before measuring, select an appropriate tool and estimate the number of units.
- Part B. Compare their estimates to the actual measurement. Include a comparison of the number of units based on the tool selected.
Instructional Items
Instructional Item 1
Nancy measured her index card using a ruler. She thinks the index card is about 9 cm. long. Is Nancy’s work correct? Explain why or why not.
*The strategies, tasks and items included in the B1G-M are examples and should not be considered comprehensive