# Lua: Math and Variables

There are three kinds of variables in Lua:

1. global variables
2. local variables
3. table fields

#### Example: Basic math with variables

``````
x = 10
y = 5
total = x + y
print("Total: ", total)
``````

Output:

Total:   15

#### Example: Math libary and Absolute Value

``````
x = -10
print("Absolute value of x: ", math.abs(x))
``````

Output:

Absolute value of x:    10

The math library contains many functions.

• math.abs
• math.acos
• math.asin
• math.atan
• math.ceil
• math.cos
• math.deg
• math.exp
• math.floor
• math.fmod
• math.huge
• math.log
• math.max
• math.maxinteger
• math.min
• math.mininteger
• math.modf
• math.pi
• math.random
• math.randomseed
• math.sin
• math.sqrt
• math.tan
• math.tointeger
• math.type
• math.ult

#### Example: More Basic Math and Comments/Remarks

The double hyphen (--) is the symbols to create a comment/remark in Lua.

``````
-- This is a sample Lua program with math
print("5 plus 4 is: " .. 5+4)
print("2 times 4.4 is: " .. 2*4.4)
``````

Output:

5 plus 4 is: 9
2 times 4.4 is: 8.8