Scalars are numbers that are used to measure size, or how big or small something is.
They represent the magnitude of a quantity such 12.5 miles, or 34 degrees C.
Numbers that are not scalars
Numbers that are used to count things are not considered scalars, although you can do arithmetic with them.
For example 2 apples + 3 apples = 5 apples.
For more see
Identifying numbers are not scalars and are used to identify something or act as an identifying label.
For example a phone number, or student id number are not scalars. You cannot do arithmetic with them. For example,
dividing a phone number by three has no meaning.
Other number topics
Numbers that have factors
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