## C++ Tutorial #3 — Order of operations, Simple interest, compounding interest

Topics covered: Order of operations in C++, simple interest formula / calculation, compounding interest formula calculation

Source code:

``````#include <iostream>
using namespace std;

int main(){

//PEMDAS
//In math -- Parenthesis, Exponents, Mult / division, add / sub
//In C++ Paren. -- Evaluated first
//Mult / Div
//Add / Sub -- Last in priority
//Evaluates left to right

//1*5-4*3
//5-12
double principal=0, rate=0, time=0;

cout << "What is the initial investment?  ";
cin >> principal;

cout << "What is annual percentage yield (APY -- APR)?  ";
cin >> rate;

cout << "How many years will this be invested for? ";
cin >> time;

cout << "The amount of money at the end of the time period will be: ";

return (0);
}``````

Order of operations
In C++, there is an order of operations, much like the one that we see in traditional mathematics. In C++, the order of operations is as follows:

1. Parenthesis
2. Multiplication and Division
The Cmath library contains a lot of useful things, for instance square root (sqrt) floating point modulo (fmod / fmodf) and more. In this case we are using ‘pow’ which is used like this: `pow(double, int);`