资料来源 : Webster's Revised Unabridged Dictionary (1913)

Present value \Pres"ent value\ or worth \worth\ (of money
   payable at a future date).
   The principal which, drawing interest at a given rate, will
   amount to the given sum at the date on which this is to be
   paid; thus, interest being at 6%, the present value of $106
   due one year hence is $100.