#### Measurement as a Generalization - Unpacked with its Concepts

Objects have properties or attributes that can be measured with different accuracies depending on the selection and use of a measurement system, units, tools, and purpose of the measurement.

Measuring is a process that starts with the identification of something to measure - a property of an object or event, then a selection of a measuring system and appropriate unit (standard or non standard), and finally a process to iterate the unit across the unknown object or event to be measured.

### Primary

• Properties can be counted.
• Conservation of number - the number of objects does not change with the position of the objects.
• Conservation of length - length of an object does not change when its position is changed or its shape is altered by bending.
• Objects can be used to compare other objects.
• Measurement is a way of detecting change.
• Linear measurement is the distance between two points.
• Volume is the measurement of space an object occupies.
• Area measures the surface of an object.
• A standard unit of measurement helps communication.
• When the thermometer goes up the temperature is hotter.
• Measurement helps in making better observations.
• Scales measure mass and weight.
• Measuring cups measure volume
• Measurements can be compared.
• Measurement is used in everyday life (recipes, plans, designing, building)
• Time is the measurement of years divided into seconds, minutes, hours, days, weeks, months, decades, centuries.
• Mathematics can be used to solve problems with time.
• Time is communicated in standard units.
• The duration of an event from the beginning to the end is measured in time.
• Time represents past, present, and future events.

### Intermediate

• Conservation of volume - volume of an object or substance does not change when the position and shape of the object or substance change position.
• Conservation of mass - mass of an object or substance does not change when the postion or shape of the object or substance changes.
• Conservation of area - area of a surface does not change when the position of the surface changes position.
• Properties and change of properties can be quantified.
• All measurement is relative to a unit, usually a standard unit.
• Scale is proportional.
• Measurement helps in making more accurate observations.
• Quantitative estimates of familiar lengths, weights, and time intervals can be confirmed by measurement.
• Measurement helps in making better observations.
• Rulers are used to measure linear measurement.
• Scales measure mass and weight.
• Measuring cups measure volume.
• Measurements can be compared.
• Measurement is used in everyday life (recipes, plans, designing, building).
• Rate is based on time.
• Standard units include:
• Linear measurement standard units are cm, m, km, inch, foot, yard, mile
• Volume- standard units include liter, ml, cup, pint, quart, gallon
• Time - measure in units of seconds, minutes, hours, days, weeks, months, years, decades, centuries. Time is used to order events. Twenty-four hours in a day, about 30 days in a month, 365 days in a year, 52 weeks in a year, 12 months in a year. Calendar is used to measure time. Clocks are used to measure time. Clocks can be analog and digital. A day is divided into daytime and nighttime. Time is determined by Earth's movement. Time is cyclic (seasons, days of weeks, months).
• Temperature measures hot and cold. Degrees in Celsius and Fahrenheit are standard units of temperature
• Mass - standard units are g, kg, pounds, ounces, tons

### Middle

• All measurement has error.
• Scale is a proportional relationship of characteristics, properties, or relationships within a system as its dimensions are increased or decreased.
• Rate involves a measure of change for a part relative to a whole (birth rate as part of population growth and comparing one measured quantity to another measured quantity (km per hour).