OPERATOR               OPERATION PERFORMED 
--------               -------------------
+                      Addition        
-                      Substraction
*                      Multiplication
/                      Division
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FUNCTION               RETURNS
--------               -------
cei(n)                 Nearest whole integer greater than or equal
                       to number.
floor(n)               Largest integer equal to or less n.
mod(m,n)               Remainder of m divided by n, if n=0 then m
                       returned.
power(m,n)             Number m raised to the power of n.
round(m,n)             Result rounded to m places to the right of 
                       the decimal point.
sign(n)                if n = 0, returns 0; if n > 0 returns 1;
                       if n < 0 returns -1.
sqrt(n)                Square root of n 
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