why............... it's woking look my last cellphone nubmer is 9 so 9*2=18 18+5=23 23*50=1150 my age is 18 so 1150+18=1168 1168+365=1533 1533-615=918 reasult == 918 look well 9 is my cellphone last number and 18 is my age it's woking