For example,

Find the mode of the following set:

15, 14, 8, 15, 16

The mode is 15 because it shows up twice

8, 5, 8, 2, 1, 8, 4

The mode is 8 because it occurs 3 times.

Sometimes, sets may have more than one mode as the following sets show

2, 4, 3, 4, 5, 6, 7, 8, 10, 6

Put the set in order

2, 3, 4, 4, 5, 6, 6, 7, 8, 10

The set above has 2 modes because both 4 and 6 occurred twice.

10, 15, 13, 11, 13, 16, 13, 10, 15, 14, 15, 18, 11, 20, 9, 11, 12

After putting the set in order, we get:

9, 10, 10, 11, 11, 11, 12, 13, 13, 13, 14, 15, 15, 15, 16, 18, 20

Here, we have 3 mode because 11, 13, and 15 occurred 3 times.

Notice, and

It is because 10 is not among the most occurring numbers like 13, which occurred 3 times.