# 6-GM-3-1

6.GM.3.1 Estimate weights, capacities and geometric measurements using benchmarks in customary and metric measurement systems with appropriate units.

In a Nutshell

It will be necessary to build on studentsâ€™ prior knowledge of measurements and units to build a solid foundation to make necessary estimations using benchmarks. Many students have not been exposed to metric units and do not understand their individual values. Similarly, students will need to build fluency through exposure to customary units that may be less familiar. Consistent exposure to both metric and customary units and discussion of relative sizes will assist students with making generalizations and estimations.

## Teacher Actions

• Make conjectures and generalizations when comparing the size of benchmark units and differing measurement units.

• Develop mathematical reasoning through discussion and hands on exposure to measurement in order to use estimation to form mental pictures and assess reasonableness of answers.

• Use and connect mathematical representations frequently and in multiple ways to facilitate a deep understanding of the concept of measurement.  Help students have hands on experience in measurement, with both customary and metric measurement systems.  (Ex: Have students measure with both a yardstick and a meter stick.) This will help to form mental pictures and understand the size of benchmark units.

## Misconceptions

• How to compare the relative measurements of benchmark units. (Ex: 1 ton > 1 lb)

• The difference between capacity, weight and other geometric measurements.

• How to select the appropriate unit of measurement (Ex: When estimating the weight of a pencil, students would use ounces instead of tons, or grams instead of kilograms.)

• Not have a basic understanding of the relative sizes of benchmark units.

• Not be able to choose the appropriate measurement unit for a given situation.

• Have trouble understanding values in the metric system.  (How big is a liter, gram, etc.)

OKMath Framework Introduction