hi i'm trying to convert the users input from dollars to cents. every time it just prints exactly what i typed in, so if i enter 0.20, the output is 0.200000. my math.h seems to be having no effect but i cannot see why.

#include <cs50.h>
#include <stdio.h>
#include <math.h>

int main(void)

    float dollars;
    int counter;
    int change;
        dollars = get_float("How much change? ");     //prompts for amount of change
    while (dollars < 0);    //checks for positive sum
    change = roundf(dollars * 100);
    printf("%i\n", change);


2 Answers 2


You are typing roundf which is not correct. It isround() declared in math.h header file


seemed to be a compiling issue and nothing i was doing was being updated despite running 'make cash' about 100 times. reloaded browser and works fine

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