#include <stdlib.h>
#include <math.h>
10 + 20 // 30
20 - 10 // 10
10 * 20 // 200
20 / 10 // 2
// power require math.h
pow(10, 2) // 100.00000
// floating point conversion
10.0 + (10 + 20) // 40.000000
// NOTE: char is promoted to int value
'c' + 10
// 109 (ascii value of c is 99)
// floating point conversion using type casting
(double) 10.0 + (10 + 20) // 40.000000
(double) 20.0 - (10 + 10) // 0.000000
(double) 10.0 * (10 * 2) // 200.000000
// common division error
30 / 20 // 1
(double) 30 / 20 // 1.500000
// integer divison, quotient
20 / 20 // 1
30 / 20 // 1
40 / 20 // 2
// modulo, remainder
10 % 20 // 10
// module, remainder on floating point
fmod(12.5, 10.0) // 2.500000
// built-ins
abs(-20) // 20
// rounding value
round(2.945) // 3.000000
round(2.495) // 2.000000
// NOTE: no built-ins for round to decimal places
// increment and decrement
int a = 10;
a++ // 11
a-- // 9