Measurement

Lesson 2: Measurement and Scientific Tools

​What is the difference between a description and an explanation?

A description is a spoken or written summary of observations. These should include facts, not opinions or interpretations.

​

​An explanation is an interpretation of observations. In other words, this is an attempt at telling what mechanisms cause some event, what processes might be occurring, and how that data matters.

​Scientists Use SI Units

​The International System of Units

​is often called the "metric system"

​in the United States. These units

​are used by scientists around the

​world in order to standardize measurements and reduce the

​amount of unnecessary time

​wasting conversions.

All Scientific Tools Have Some Measure of Uncertainty

​Some tools have greater precision than others and scientists use those tools where they can, but in the end, we must account for some margin of error, however slight it is.

​Scientific Notation

Scientific notation is used to describe really large numbers (such as the mass of the sun) and really tiny numbers (such as the diameter of an atom).

​

​It makes numbers easier to read and write. 6,200,000,000,000 pounds can be written 6.2 x 10¹⁸ instead.

Multiple Choice

A(n) ________________ provides a written summary of observations without opinion or interpretation.

• description

• explanation

• experiment

• survey

Multiple Choice

True or False: All measurements taken using tools are perfectly accurate.

• True

• False

Multiple Choice

Scientists use _______ units.

• SI

• English

• European

• Polish

​Percent Error

When scientists take

measurements, they

try to accurately

calculate the error in

any experimental

measurements. Percent

Error ​tells us how far

​off, in percentage of

​accepted value, a

​measurement is.

​Various Tools Used by Scientists

• ​Journal

• ​Balances for measuring mass

• ​Glassware such as beakers and test tubes

• ​Thermometers

• ​Calculators

• ​Computers for analyzing data or running simulations

• ​Stopwatches

• ​Hot Plates

• ​pH strips

• ​Spring scales

Multiple Choice

Scientists use _________________ notation to abbreviate really big and really small numbers.

• scientific

• medical

• colloquial

• stereotypical

Multiple Choice

True or False: Percent error tells us how much our measurement was off from an accepted measurement.

• True

• False