# Grade calculations

*Note: You are currently viewing documentation for Moodle 2.3. Up-to-date documentation for the latest stable version is available here: Grade calculations.*

## Contents

## Enabling Calculations

To enable calculations for you gradebook:

- Login as teacher or other user with permission to edit grades.
- Go to course.
- Click on
*Grades*in the Administration block. - Click the "Turn Editing On" button on the top right corner.
- Click the "Show Calculations" icon on the middle top.
- Click the little calculator symbol under Course Total column which will bring you to the calculations page.

## Assigning ID Numbers

ID numbers are similar to nicknames for each grade item. In a calculation, instead of referring back to a whole assignment name, we can substitute it for it's ID number which becomes a lot easier. Think of it as substituting 143 as X and then using X for various math problems.

ID numbers on the bottom of the page. Use simple to remember numbers or variables like 1, X, or Quiz1. Remember to click "Add id numbers"!

## Understanding Calculation Functions

Click the yellow question mark next to the word "Calculation". This will bring a pop-up explaining the various functions that can be used in calculations and how to use them.

Every calculation must start with an equal sign (=). Following is a list of the functions supported by the calculation. The comma (,) character is used to separate arguments within function brackets. The comma can also be used to separate different functions.

- average([[item1]], [[item2]]...): Returns the average of a sample
- max([[item1]], [[item2]]...): Returns the maximum value in a list of arguments
- min([[item1]], [[item2]]...): Returns the minimum value in a list of arguments
- mod(dividend, divisor): Calculates the remainder of a division
- pi(): Returns the value of the number Pi
- power(base, power): Raises a number to the power of another
- round(number, count): Rounds a number to a predefined accuracy
- sum([[item1]], [[item2]]...): Returns the sum of all arguments

A number of mathematical functions is also supported:

- sin
- sinh
- arcsin
- asin
- arcsinh
- asinh
- cos
- cosh
- arccos
- acos
- arccosh
- acosh
- tan
- tanh
- arctan
- atan
- arctanh
- atanh
- sqrt
- abs
- ln
- log
- exp

## Making your Calculation

Back on the calculations page, start typing the various functions and the ID numbers chosen for your calculation.

- Start with an equal sign (=)
- Choose a function; Example: =sum()
- Plug in your ID numbers enclosed in 2 hard brackets; Example: =sum([[item1]][[item2]][[item3]])
- Separate each ID number with a comma; Example: =sum([[item1]],[[item2]],[[item3]])
- Click the "Save Changes" button.