Mode: the numbers that occurs the most in a set of data.
Although it's optional, I prefer to list the numbers in order from least to greatest because it makes it easier to see what number occurs the most.
Least to greatest - 26,26,36,54,78
The mode of this set of data is 26. The number 26 occurs twice and no other number occurs more than once in that set of data.
The mode for this set of numbers is 26.
