# Document 17550954

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There are two types of measurement
 Quantitative measurements have a definite form
and are usually expressed as numbers with units.
▪ E.g. 3.05 grams, 12 liters, 4.5 grams/ml
 Qualitative measurements are descriptive and
have no numbers involved.
▪ E.g. It gave off a “reddish gas”, It had small bumps
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Measurements can be either direct or
derived.
 Direct measurement can be taken straight from
an object.
▪ E.g. The length of an object in meters
 Derived measurements must have a
mathematical expression performed using several
direct measurements
▪ E.g. The volume of an object is length x width x height
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Density is a very important derived
measurement.
 Density = Mass
Volume
Density is an example of an intensive property
because it does not depend on how much of the
object you have on hand.
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How do you know if your measurement are
true or not?
 Accurate measurements are measurements that
are very close to the true value of a measurement.
 Precise measurements are measurements that
are consistent, but not necessarily close to the
true value.
 The goal is to have measurements that are both
accurate and precise.
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Think of a dart board.