下表列出了所有的Lua语言支持的算术运算符。假设变量A持有10和变量B持有20，则：
| 运算符 | 描述 | 示例 |
|---|---|---|
| + | 两个操作数相加 | A + B = 30 |
| - | 从所述的第一个减去第二操作数 | A - B = -10 |
| * | 两个操作数相乘 | A * B = 200 |
| / | 通过分子除以反分子 | B / A = 2 |
| % | 模运算和整数除法后的余数 | B % A = 0 |
| ^ | 指数运算符需要的指数 | A^2 = 100 |
| - | 一元运算 - 运算符相当于取反 | -A = -10 |
试试下面的例子就明白了所有的Lua编程语言提供了算术运算符：
a = 21
b = 10
c = a + b
print("Line 1 - Value of c is ", c )
c = a - b
print("Line 2 - Value of c is ", c )
c = a * b
print("Line 3 - Value of c is ", c )
c = a / b
print("Line 4 - Value of c is ", c )
c = a % b
print("Line 5 - Value of c is ", c )
c = a^2
print("Line 6 - Value of c is ", c )
c = -a
print("Line 7 - Value of c is ", c )
当执行上面的程序，它会产生以下结果：
Line 1 - Value of c is 31 Line 2 - Value of c is 11 Line 3 - Value of c is 210 Line 4 - Value of c is 2.1 Line 5 - Value of c is 1 Line 6 - Value of c is 441 Line 7 - Value of c is -21
