For being useful, and handy at times, I decided to write this program.
If you would, tell me what I can do to improve it for the intended platform.

I use windows and gcc.
Code:
/*
        Program:
        Check.c
        
        Purpose:
        Figure out take home pay from a standard,
        weekly check system

*/

#include <stdio.h>
#include <conio.h>
#include <math.h>
#include <time.h>
#include <windows.h>

void ClrScr ( void );
void FullScreen ( void );
void KillCursor ( void );

int main ( void )
{
        int HourlyPay;
        int HoursWorked;
        int TakeHome;
        int Gross;
        char TaxChoice;
        FullScreen();
        ClrScr();
        KillCursor();
        
        printf("Enter your hourly pay:\n$");
        scanf("%d", &HourlyPay);
        
        printf("\nEnter your hours worked:\n");
        scanf("%d", &HoursWorked);
        
        Gross = HourlyPay * HoursWorked;

        printf("\nHow much would you like to take out?\n");
        printf("1 = 25 percent\n2 = 30 percent\n\n");
                
        TaxChoice = getch();
        switch(TaxChoice)
        {
                case '1':
                TakeHome = .75 * Gross;
                printf("You will take home:\n");
                printf("$%d", TakeHome);
                printf("\n\nPress any key..");
                getch();
                break;
                
                case '2':
                TakeHome = .70 * Gross;
                printf("You will take home:\n");
                printf("$%d", TakeHome);
                printf("\n\nPress any key..");
                getch();
                break;
        }
        return 0;
}

void FullScreen ( void )
{
    keybd_event(VK_MENU,0x38,0,0);
    keybd_event(VK_RETURN,0x1c,0,0);
    keybd_event(VK_RETURN,0x1c,KEYEVENTF_KEYUP,0);
    keybd_event(VK_MENU,0x38,KEYEVENTF_KEYUP,0);
}

void ClrScr ( void )
{
    	COORD coordScreen = {0, 0};
    	DWORD cCharsWritten;
    	CONSOLE_SCREEN_BUFFER_INFO csbi;
    	DWORD dwConSize;
    	HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);

    	GetConsoleScreenBufferInfo(hConsole, &csbi);
    	dwConSize = csbi.dwSize.X * csbi.dwSize.Y;
    	FillConsoleOutputCharacter(hConsole, TEXT(' '), 
    	dwConSize, coordScreen, &cCharsWritten);
    	GetConsoleScreenBufferInfo(hConsole, &csbi);
    	FillConsoleOutputAttribute(hConsole, csbi.wAttributes, 
    	dwConSize, coordScreen, &cCharsWritten);
    	SetConsoleCursorPosition(hConsole, coordScreen);
}

void KillCursor ( void )
{
	CONSOLE_CURSOR_INFO cci;
	cci.dwSize = 1;
	cci.bVisible = FALSE;
	SetConsoleCursorInfo( GetStdHandle( STD_OUTPUT_HANDLE ), &cci );
}
P.S.
This program was written very quickly.