__Mean
__To find the mean of a group of numbers we
find their average

example: A group of numbers 1,3,8,6,8

mean = (1+3+6+8+8)/5 = 5.2

__Median
__To find the median of a group of numbers we arrange
the numbers in increasing order and look for the number
in the middle.

example: A group of numbers 1,3,8,6,8

re-arrange: 1,3,6,8,8

6 being in the middle is the median.

__Mode
__To find the mode we look for the number which appears
for the most number of times in a group of numbers.

example: A group of numbers 1,3,8,6,8

8 is the number which appears twice, which is more than the other numbers in the list hence it is the mode.

__Range
__To find the range we find the difference between the
largest number and the smallest number in the group.

example: A group of numbers 1,3,8,6,8

8 is the largest and 1 the smallest number

hence range is 8 – 1 = 7