Arithmetic operator

(Redirected from Basic math)

Roblox Lua can do mathematical calculations, much like any calculator. In Lua, there are the following arithmetic operators:

Symbol Operation Example
+ Addition 2 + 3 = 5
- Subtraction 5 - 2 = 3
* Multiplication 5 * 2 = 10
/ Division 8 / 2 = 4
- Unary Negation -(20) = -20
^ Exponentiation 5 ^ 3 = 5 * 5 * 5 = 125
 % Modulus 11 % 3 = 2


print(2 + 3)
print(5 - 2)
print(5 * 2)
print(8 / 2)
print(-(20))
print(23 % 4)
5
3
10
4
-20
3


Parentheses[edit]

Parentheses can be used in Lua. If you want something calculated first, put it in parentheses.

Example:

print((10 / 20) / 5) -- is equal to .5 / 5, which is .1
print(10 / (20 / 5)) -- is equal to 10 / 4, which is 2.5

Following the associative properties of multiplication and addition, it does not matter how you organize the parentheses in certain instances.

Example:

print((10 + 20) + 5) -- is equal to 30 + 5, which is 35
print(10 + (20 + 5)) -- is equal to 10 + 25, which is 35
 
print((10 * 20) * 5) -- is equal to 200 * 5, which is 1000
print(10 * (20 * 5)) -- is equal to 10 * 100, which is 1000

Precedence[edit]

Main article: Precedence

For the mathematic operators, Lua follows the same rules as the ones usually followed in mathematics, the ones you have been taught or will be taught at school, with the modulus operator having the same priority as multiplication and division. That means mathematic operations will be executed in the order below:

  1. Exponentiation (^)
  2. Unary Negation (-)
  3. Multiplication, division and modulus (*, / and %)
  4. Addition and subtraction (+ and -)

Just like in normal math, you can use parenthesis to change the order.

Note that multiplication and division have the same precedence, as well as addition and subtraction. This means that they will occur in whatever order they appear from left-to-right after exponents, not necessarily multiplication and then division.

See Also[edit]

Practice[edit]

Exercise

Instructions

Make a script that prints the remainder of 9 cubed divided by 5 plus 13 squared. Write the full expression in the print() function.

Solution
Select
print((9 ^ 3) % (5 + 13 ^ 2))