//FACTOR = (65536 / 10) = 6554
#define FACTOR  (6554UL)
#define MULLL(a,b)   ((((unsigned long)(a)*FACTOR ) >> 16UL )*  \
                        (unsigned long)(b))
unsigned int cc1 = 1000;
C_task main( void )
 {
  //Вызрв MULLL( (INTмножимое), (INT)(FLOATмножитель*10) )
  printf("1000*0.3=%d\n",MULLL(cc1,3)); // ( (a*10)*(b*10) ) / 10
  printf("1000*0.4=%d\n",MULLL(cc1,4));
  printf("1000*0.5=%d\n",MULLL(cc1,5));
  printf("1000*1.5=%d\n",MULLL(cc1,15));
  printf("1000*2.5=%d\n",MULLL(cc1,25)); 
 }