The term "range" has a number of meanings depending on the context.
Range in statistics
In statistics, the range is the difference between the greatest number and the least number in a set of data.
Ritchie earned the following scores in his gymnastics events:
Thus, the range in Ritchie's scores is 0.5.
Range (interval) in mathematics
The term range is commonly used in mathematics to refer to an interval. An interval in this context is the set of real numbers that lie between two numbers.
If we say that the range is some set of numbers, n, between and including 0 and 100, this means that our range is 0, 100, and all of the numbers between 0 and 100. This is written as:
0 ≤ n ≤ 100
This is referred to as a closed interval, because it does include the endpoints. It can also be written as [0, 100].
If instead we were to write:
0 < n < 100
The range would be all the numbers between 0 and 100, but not including 0 and 100. This is referred to as an open interval because it doesn't include the endpoints. It can also be written as (0, 100).
We could also have a range of (0, 100] or 0 < n ≤ 100 and [0, 100) or 0 ≤ n < 100.