This article describes how to perform basic mathematical functions on variables in Displayr using the **Calculation** menu. These functions include Divide, Multiply, Subtract, Average, Sum, Maximum, Minimum, Any of, None of, Count, Standard Deviation, and Variance.

## Requirements

- A Displayr document with a data set.
- Numeric variables. In this example, we have a numeric grid variable set called
*Q2 - No. of colas consumed*which we will use for these calculations:

## Method - Divide, Multiply, Subtract

1. Select one or two variables in the **Data Sets** tree that you wish to use in your calculation. For example, let's select the *Coca-Cola - When 'out and about'* and *Coca-Cola - When 'at home'* variables. Note, the order you select these variables determines where they are placed in the calculation.

2. Go to **Calculation > Divide**/**Multiply** or **Subtract** in the toolbar.

3. A new variable will be created directly after the selected variable set(s) which applies the specified formula on the selected variable(s).

4. OPTIONAL: When you select the new variable, in the **object inspector** it will display the variables that have been used. You can change the variables by using the relevant drop-down.

5. OPTIONAL: If you only select a single variable, it will default to a **Single numeric value** of **1** for the second reference. You can change this value as required to update your calculation.

6. OPTIONAL: You can additionally switch either reference between a **Variable** and a** Single numeric value** if required.

Note, if you perform this on nominal variables, the calculation will use the underlying values.

## Method - Average, Sum, Maximum, Minimum, Any of, None of, Count, Standard Deviation, Variance

1. Select the variables in the **Data Sets** tree that you wish to use in your calculation. For example, let's select all the *Coca-Cola *variables from the* When 'out and about'* group. Note, the order you select these variables determines where they are placed in the calculation.

2. Go to **Calculation** in the toolbar and select** Average**, **Sum**,** Maximum**, **Minimum**, **Any of**, **None of**, **Count**, **Standard Deviation **or **Variance **in both sub-menus, e.g. **Average > Average**.

3. A new variable will be created directly after the selected variable set(s) which applies the specified formula on the selected variable(s).

4. OPTIONAL: When you select the new variable, in the **object inspector** it will display the variables that have been used. You can change, remove or add to the variables drop-down as required:

5. OPTIONAL: Untick **Calculate for observations with incomplete data** if you wish to return missing for any record that has missing data in any of the selected variables.

6. OPTIONAL: For the **Any of**, **None of** and **Count** options where you are working with numeric data, you can additionally adjust **Values to count**. This takes the format of individual specified values or a range of values, e.g. *0-10* or *1,2,3* or *>1*. When working with categorical data, you instead specify the **Categorical labels** to include.

## Next

How to Create a Custom R Text Variable

How to Create a Custom Numeric R Variable

How to Perform Mathematical Calculations on Tables

How to Perform Mathematical Calculations Using R

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