### Standard 13: Measurement

In grades 5-8, the mathematics curriculum should include extensive concrete experiences using measurement so that students can:
• Extend their understanding of the process of measurement
• Benchmarks 9A (The Mathematical World: Numbers)
Grades 3-5, page 212
Measurements are always likely to give slightly different numbers, even if what is being measured stays the same.

Benchmarks 3A (The Nature of Technology: Technology and Science)
Grades 3-5, page 45
Measuring instruments can be used to gather accurate information for making scientific comparisons of objects and events and for designing and constructing things that will work properly.

• Select appropriate units and tools to measure to the degree of accuracy required in a particular situation
• Benchmarks 1B (The Nature of Science: Scientific Inquiry)
Grades K-2, page 10
Tools such as thermometers, magnifiers, rulers, or balances often give more information about things than can be obtained by just observing things without their help.

• Understand the structure and use of systems of measurement
• Benchmarks 9A (The Mathematical World: Numbers)
Grades 3-5, page 212
When people care about what is being counted or measured, it is important for them to say what the units are (three degrees Fahrenheit is different from three centimeters, three miles from three miles per hour).

Benchmarks 12B (Habits of Mind: Computation and Estimation)
Grades 3-5, page 290
Judge whether measurements and computations of quantities such as length, area, volume, weight, or time are reasonable in a familiar context by comparing them to typical values.

Benchmarks 11D (Common Themes: Scale)
Grades 6-8, page 278
Properties of systems that depend on volume, such as capacity and weight, change out of proportion to properties that depend on area, such as strength or surface processes.

• Develop the concepts of rates and other derived and indirect measurements
• Benchmarks 9B (The Mathematical World: Symbolic Relationships)
Grades 6-8, page 219
Mathematical statements can be used to describe how one quantity changes when another changes. Rates of change can be computed from magnitudes and vice versa..

Benchmarks 12B (Habits of Mind: Computation and Estimation)
Grades 6-8, page 291
Determine what unit (such as seconds, square inches, or dollars per tankful) an answer should be expressed in from the units of the inputs, and be able to convert compound units (such as yen per dollar into dollar per yen, or miles per hour into feet per second).

• Make and use measurements in problems and everyday situations
• Benchmarks 12C (Habits of Mind: Manipulation and Observation)
Grades 3-5, page 293
Measure and mix dry and liquid materials (in the kitchen, garage, or laboratory) in prescribed amounts, exercising reasonable safety.