Shopping practise C++ answer keeps coming out negative

Question

#include <iostream>
using namespace std;

int main() {
// your account's balance
auto balance = 2452.4;
// price for each notebook
auto price = 259.99;

// Task: calculate the number of notebooks you can afford and output it.
// Hint: use an integer to store the result.

int notebooks = balance/price;
cout << notebooks;
cout<< endl;

// Task: calculate the amount left over on your account after the purchase and output it on a new line.
// Hint: calculate the total price of the purchase, then substract it from the balance.

auto newbalance = notebooks * price;
auto newBalance = newbalance - balance;

cout << newBalance;
}

Answer spits out
9
-112.49
I separated the variables thinking that might have caused it with no luck

Answer 1

it's negative because you're subtracting in the wrong order. it's not newbalance when you compute notebooks * price, it's cost. you subtract cost from balance to find out how much is left.

#include <iostream>
using namespace std;

int main() {
auto balance = 2452.4;
auto price = 259.99;

int notebooks = balance/price;
cout << notebooks << endl;

auto cost = notebooks * price;
cout << cost << endl;
balance -= cost;

cout << balance;
}