=SUM(GRADING_TRACTOR*E3)

KEEP IN MIND THAT I ENTER GRADING TRACTOR IN CELL A1.
CELL E3 HAS THE NUMBER 8 AND CELL F3 HAS THE ABOVE FORMULA.

NOW IF I CHANGE CELL A1 FROM A GRADING TRACTOR TO LABOR WITH THE VALUE OF
($28) HOW CAN I MAKE MY FORMULA IN CALL F3 DISTINGUISH THAT WITH OUT HAVE TO
CHANGE THE FORMULA MANUALLY.

THANK YOU VERY MUCH