Math

if last digit is even (0, 2, 4, 6, or 8)

if the sum of the digit is divisible by 3

if the number is divisible by both 2 AND 3

if the sum of the digits is divisible by 9

if the last digit is 0 or 5

if the last digit is 0

if the last two digits are divisible by 4 (not always true)

if the last three digits are divisible by 8

the number that occurs most often

The largest number minus the lowest number

The number that falls in the middle of the data set.  The data set is arranged from least to greatest or greatest to least to highest number; i.e. 47, 78, 78, 82, 88, 100, the median would be 80

Add numbers and divide by how many numbers there are.