## The Lesson

We can find the mode of a set of numbers. Imagine a teacher wanted to find the class's average test score in mathematics.

## How to Find the Mode

The mode is found by counting how often each number appears in a set and selecting the one that appears most often.

## Question

What is the mode of the test scores below?

# 1

List the numbers in numerical order (going from the smallest to the largest number).
6 7 7 9 10

# 2

Count how often each number appears.
• 6 appears 1 time.
• 7 appears 2 times.
• 9 appears 1 time.
• 10 appears 1 time.

# 3

Find the number that appears most often.

The mode of the test scores is 7.

## How Find the Mode When There Is More Than One

Sometimes there is more than one mode in a set of numbers.

## Question

What is the mode of the test scores below?

# 1

List the numbers in numerical order (going from the smallest to the largest number).
6 7 7 9 10 10

# 2

Count how often each number appears.
• 6 appears 1 time.
• 7 appears 2 times.
• 9 appears 1 time.
• 10 appears 2 times.

# 3

Find the number that appears most often.

The modes of the test scores are 7 and 10.

## Lesson Slides

The slider below gives another example of finding the mode.

## The Mode Is The Most

Remember, the mode is the number that appears most!

## There Isn't Always a Mode

Unlike the mean and median, there isn't always a mode.

If all numbers appear equally as often, there is no mode.

## Unimodal, Bimodal, Multimodal

• A set of data with one mode is unimodal:

In the set above, 1 occurs most often, more than any other number. There is only one mode.
• A set of data with two modes is bimodal:

In the set above, 1 and 2 both occur the same number of times, which is more than any other number. There are two modes.
• A set of data with more than one modes is multimodal:

In the set above, 1, 2 and 3 all occur the same number of times, which is more than any other number.

## How to Find the Mode from a Frequency Table

Sometimes data is presented in frequency tables. A frequency table representing the test scores is shown below:

It is possible to find that the mode of the test scores is 7.