The range is the difference between the least and greatest numbers in the set.

Example: Consider the following set: 118, 154, 196, 211, 253.
The least number in the set is 118 and the greatest is 253. The range is the difference between these two numbers: 253 - 118 = 135. So, 135 is the range.

Finding mean, median, mode and range from a chart:
A chart is something we use to organize and see numbers better.
Here's a chart that shows 4 children and how many siblings they have:

 Child Siblings Abby 1 Bob 3 Caitlyn 2 Dan 2

Mean: Adding all the siblings and divide by the amount of kids.
1 + 3 + 2 + 2 = 8
The, 8 ÷ 4 = 2
So, 2 is the mean.

Median: Put the siblings in order from low to high and then find the middle number.
1,2,2,3
Since there are two middle numbers, we have to find their mean:
2 + 2= 4
4 ÷ 2= 2
So, 2 is the median.

Mode: Finding the number of siblings that comes up most often.
1, 3, 2, 2 = 2
So, 2 is the mode.

Range: Finding the difference between the least and greatest number of siblings in the set.
3 - 1 = 2
Hence, 2 is the range.