# How to Make a Grouped Frequency Table (Mathematics Lesson)

# Making a Grouped Frequency Table

A grouped frequency table is a great way to present a lot of data.Imagine a teacher collected the test scores of their mathematics class:

Depending on each student's test score, the teacher will assign a grade:

# How to Make a Grouped Frequency Table

Making a grouped frequency table is easy.#### An Example Question

Construct a grouped frequency table for the numbers below.Step 1

Step 2

**Score**column, write the groups of numbers. In our example, we will use the group of test scores assigned to the different grades.

Step 3

**Question**. For each number, see which of the group of numbers it belongs in. Cross it out and put a tally mark in the

**Tally**column, in the row for that group of numbers.

- The first number is 2. It belongs in the
**1 - 5**group. Cross it out and put a tally mark in the**Tally**column in the**1 - 5**row.

- The second number is 10. It belongs in the
**6 - 10**group. Cross it out and put a tally mark in the**Tally**column in the**6 - 10**row.

- Continue until all numbers have been crossed out and had tally marks placed in the
**Tally**column.

Step 4

**Frequency**column.

This is the grouped frequency table for the set of numbers given in the question.

# A Real Example of How to Make a Grouped Frequency Table

The slider below gives another example of making a grouped frequency table.# Finding Averages from a Grouped Frequency Table

The grouped frequency table can be used to find the average of a set of numbers.A frequency table can be used to find: Read more about how to find the mean from a grouped frequency table.

Read more about how to find the median group from a grouped frequency table.

Read more about how to find the mode group from a grouped frequency table.

##### Note

# What Is a Grouped Frequency Table?

A grouped frequency table is a frequency table where the numbers are grouped together.It shows you how often numbers within each group appear in a list of numbers.

# What Are Tally Marks?

Tally marks are a way of helping you to count, especially when you have to count a large set of numbers.A vertical line is made for the first four numbers:

To make five, a diagonal bar is drawn across the four vertical lines:

After five, single bars are added again:

Once ten is reached, two groups of five tally marks are used:

Finally, it is easy to count the total number of tally marks. For example, consider the tally marks below:

Count up the groups of five tally marks in fives:

Finally add, the number of single marks:

There are 22 tally marks.

##### Top Tip

# Quick Check

When there are a large number of numbers to put into a frequency table, it is easy to go wrong counting them.Crossing the numbers off as you enter them into the

**Tally**column is one way of ensuring you check each number once only.

Another useful check is to add all the numbers in the

**Frequency**column. They should sum to the number of numbers there were to begin with.

For example, if there are six numbers:

You obtain the following frequency table:

Summing up the frequency column gives

2 + 3 + 2 = 7

This is not equal to the six numbers. This tells you that a mistake has been made. (In the example above, there is only one number in the 11 - 15 group (15), not two).Try to find the mistake or repeat the exercise.

##### Note

# Counting the Numbers

In the test scores example, the numbers have been counted one at a time going from left to right.This is not the only way to do it. You could:

- Go through and count all the numbers in the 1 - 5 group. Then all the numbers in the 6 - 10 group etc.
- Order the numbers and group like numbers together.