Thread: Trying to find the original value

I know the title doesn't make a whole lot of sense and I'm going to be terrible at trying to explain it.

I'm trying to write a program that finds the original value from a percentage down and the last known value.

Example:
Bitcoin was at $4420 which was down 4.9% from last month. I'm wanting my program to calculate what that number was.

The way it's currently written, I'm aware that percents must be entered like "0.05" for 5%.

Code:

//
//  main.c
//  valuefinder
//
//  Created by Joshua Ernzen on 10/3/17.
//  Copyright © 2017 Joshua Ernzen. All rights reserved.
//
// This program is suppose to find the starting value from a percent down.
// Example: $4,420 is 4.9% down from last month. Find the original value

#include <stdio.h>
#include <stdint.h>

int main() {
    double incnumber, usernumber, numberholder, finalnumber, percent;
    int8_t loop;
    loop = 1;
    
    printf("Please enter the value: ");
    scanf("%lf", &usernumber);
    printf("Please enter the percentage: ");
    scanf("%lf", &percent);
    
    incnumber = usernumber;
    
    while(loop == 1) {
        numberholder = incnumber * percent;
        finalnumber = numberholder + incnumber;
        
        if(finalnumber - numberholder != usernumber) {
            incnumber = incnumber + 0.01;
            printf("%lf\n", incnumber);
        }
        if(finalnumber - numberholder == usernumber)
            loop = 0;
    }
    
    printf("%lf is %lf of %lf\n", usernumber, percent, finalnumber);
    
    return 0;
}

Right now when it executes, it just takes let's say the value of 5% of 95 (4.75) and just adds it to 95. This happens when I attempt to find 95 is 5% down from last week, which should be 100.

So the output of the code should look like this?

Code:

Enter current value: 4420
Enter percentage   : 4.9

Original value: 4647.74

You're better off figuring out how to solve this by hand first. This can be implemented with a simple equation.

Yes, that's suppose to be the output.

Have you attempted to solve a general case equation for this calculation?