# Count and Sum¶

Two of the most basic but most used statistics are the count and sum of a dataset.

Count Definitions

The **count** of a dataset is the number of observations in the dataset. This
applies to all variables.

Sum Definition

The **sum** of a dataset is the addition of all values in the dataset. This
applies only to quantitative variables.

## Applications and Examples¶

The reason that the count is so important is that it can be an indication of how useful the dataset is. For example, suppose you’re trying to find the average height of students at your college of 800 people, so you conduct a survey collecting students’ heights. If your survey contains only 2 heights, then using these results to calculate an average won’t be very useful, since this summary statistic is only representative of 2 students. If, however, your survey contains 600 heights, calculating an average from these results will be more reliable, since this statistic represents 600 of the 800 students.

As an example of using *count* and *sum*, suppose you are throwing a homework
party. You ask your friends to RSVP if they are attending and to submit how many
pizza slices they would like to eat, through a survey. Knowing how many people
would be attending will be helpful to you when you purchase snacks, and you can
use the *count* to calculate the number of guests. You could also take the *sum*
of the number of pizza slices your friends want in order to get a better idea of
how many pizzas to order.

Calculating these statistics in Sheets is fairly straightforward. For these and
other statistics, you’ll need to know **cell range notation**. To refer to a
range of cells in Sheets, type the first cell in the range and the last cell in
the range, separated by a colon. For example:

“A1” refers to cell A1

“A1:A6” means all cells in the A column from rows 1 through 6

“A1:D1” means all cells in the 1 row from columns A through D

“A1:D6” means all cells in rows 1 through 6 and columns A through D

Count and Sum Sheets Syntax

The

`COUNT`

function returns the number of non-empty cells in a range. The syntax is`=COUNT(cell range)`

.The

`SUM`

function returns the addition of a cell range. The syntax is`=SUM(cell range)`

.