Calculating the Mode

Contributor: Elephango Editors. Lesson ID: 10136

Have you ever eaten pie à la mode? That has nothing to do with math, but using different modes of learning and your brain, you will master modes! It will be a piece of cake and easy as pie!


Elementary, Middle School

learning style
personality style
Beaver, Golden Retriever
Grade Level
Middle School (6-8)
Lesson Type
Quick Query

Lesson Plan - Get It!

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Watch the short video below showing earthquakes shaking Northern California.

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Scientists want to know the most common magnitude of this series of earthquakes. This information will help them better prepare for any future earthquakes through the use of stronger building materials.

They need to take the mode of the scores of the last ten earthquakes.

  • Not sure how to find the mode of a set of numbers?

Keep reading to learn how to calculate the mode!

Working with numbers helps us figure out information.

For example, in the opening scenario, scientists are trying to determine the most common strength of a series of earthquakes. This information will help the scientists work with architects to build stronger buildings.

The way the scientists can get the answer is to take the Richter scores from the last ten earthquakes and find the mode among those numbers.

To understand how to find the mode in a set of numbers, you first need to understand some math vocabulary. On a piece of paper, record the following terms and definitions.

Data is information or facts, often in the form of numbers, text, or symbols, used for analysis or reference.

Mode is the value that appears most frequently in a data set.

Magnitude is the size of extent of something, often represented by a numerical value.

Value is a measure of the worth or importance of something, often quantifiable.

When trying to figure out the mode of a set of numbers, you will first need to put the data (numbers) in order from the least to the greatest.

Practice using the earthquake data from the opening scenario.

The last ten earthquakes were measured using the Richter scale, and their magnitudes are listed below.

  7.0 6.2 7.7 8.0 6.2 7.2 5.4 6.6 7.5 5.9


  • What is the mode of the list of magnitudes?

When working with data that is written in the form of decimals, make sure you look at the whole number first (the number to the left of the decimal point).

If you have more than one value that begins with the same whole number, put them in order by looking at the number to the right of the decimal.

At this point, you need to list the numbers from least to greatest and see if any numbers (values) occur more than once.

  5.4 5.9 6.2 6.2 6.6 7.0 7.2 7.5 7.7 8.0


The number in a set that occurs more than once is the mode.

In this data example, the value 6.2 occurs twice, while every other number occurs only once.

This means that 6.2 is the mode because it is the number that occurs most often in the set of numbers representing the scores of the last ten earthquakes.

  • Is it possible that a set of data can have more than one mode?


If you are working with data and notice that more than one value (number) occurs more than once, there may be more than one mode.

The important thing in determining if there is more than one mode is that each value that occurs more than once must appear the same number of times as another value to be an additional mode. Otherwise, the mode will be the value that appears the most times in the data set.

For example, find the mode of the following data.

  3 4 5 5 5 6 7 8 8 8 9 9


In that data set, the numbers 5, 8, and 9 occur more than once. But only the numbers 5 and 8 are the modes because each occurs thrice. The number 9 only occurs twice.

Remember, the mode is the number in a set of data that occurs the most.

  • Is it possible that a data set does not have a mode?


It is possible to look at a data set where each value (number) occurs only once. In that case, the correct answer would be NO MODE.

If you need a review, check out What is Mode in Math?

Now that you're in mode, continue to the Got It? section to try out your new skill!

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