Something

main(){
  7    char number[5],square[10],newnumber[10];
  8    int fd[2],fd1[2];
  9    printf("Give a number:\n");
 10    scanf("%s",number);
 11    pipe(fd);
 12    pipe(fd1);
 13    if(fork()==0){/*Child Process*/
 14       close(fd[0]);
 15       close(fd1[1]);
 16       write(fd[1],number,strlen(number)+1);
 17       read(fd1[0],newnumber,10);
 18       printf("%s NEWNUMBER !!!!!!!!!!!!!!!!!!!!\n",newnumber);
 19       double apotelesma= atof(newnumber);
 20       printf("RIZA =   %ld\n",apotelesma);
 21       close(fd1[0]);
 22       close(fd[1]);
 23    }
 24    else{/*Parent Process*/
 25       close(fd[1]);
 26       close(fd1[0]);
 27       read(fd[0],square,10);
 28       double   num=strtol(square);
 29       double x = sqrt(num);
 30       printf("%lf\n",x);
 31       char new[10];
 32       sprintf(new,"%9f",x);
 33       printf("%s\n",new);
 34       write(fd1[1],new,strlen(new)+1);
 35       close(fd[0]);
 36       close(fd1[1]);
 37    }
 38 }