Range

Range is one of the measures used to describe a dataset.  Range shows what it sounds like -- how far a dataset spans.  Range can be written as a span (e.g., from 10 to 30), but a single measure of range is simple:

Range is the dataset's maximum (highest number) minus its minimum (lowest number).

So, finding range is a simple subtraction problem.  Just make sure that you properly identify the minimum and maximum.  One off the best ways to make sure you aren't missing a number is to order the numbers (just like you would when finding a median).

Example:

Let's say you have the following dataset:

$43$, $56$, $18$, $67$, $44$, $47$

Rather than just trying to eyeball the data, order the numbers from least to greatest:

$18$, $43$, $44$, $47$, $56$, $67$

Find the minimum and maximum of the dataset:

$\bbox[5px, border:2px solid blue]{18}$, $43$, $44$, $47$, $56$, $\bbox[5px, border:2px solid green]{67}$

Subtract the minimum from the maximum:

$67-18=49$

The range of this dataset is $49$.

Remember, the range of a dataset is just what it sounds like: how far the dataset ranges, or the distance from highest to lowest datapoint.