/in/foo.c: In function 'divide':
/in/foo.c:99:25: warning: implicit declaration of function 'multiply' [-Wimplicit-function-declaration]
         char* product = multiply(alignedDivisor, temp);
                         ^~~~~~~~
/in/foo.c:99:25: warning: initialization makes pointer from integer without a cast [-Wint-conversion]
/in/foo.c:113:42: warning: passing argument 2 of 'subtract' makes pointer from integer without a cast [-Wint-conversion]
     char* remainder = subtract(dividend, multiply(quotient, divisor));
                                          ^~~~~~~~
/in/foo.c:20:7: note: expected 'char *' but argument is of type 'int'
 char* subtract(char* num1, char* num2) {
       ^~~~~~~~
/tmp/ccngattW.o: In function `divide':
foo.c:(.text+0x237): undefined reference to `multiply'
foo.c:(.text+0x27c): undefined reference to `multiply'
collect2: error: ld returned 1 exit status