U.S. National Standards
N.4. Measurement (NCTM)
4.1. Understand measurable attributes of objects and the units, systems, and processes of measurement.
4.1.1. Understand such attributes as length, area, weight, volume, and size of angle and select the appropriate type of unit for measuring each attribute.
4.1.2. Understand the need for measuring with standard units and become familiar with standard units in the customary and metric systems.
4.1.4. Understand that measurements are approximations and how differences in units affect precision.
4.2. Apply appropriate techniques, tools, and formulas to determine measurements.
4.2.2. Select and apply appropriate standard units and tools to measure length, area, volume, weight, time, temperature, and the size of angles.