Uniform series present worth, useful when operating costs and recurring benefits sometimes occur in constant or uniform amounts year after year.
P = $1,000 __1___   + $1,000 __1___   + $1,000 __1___   + $1,000 __1___
                (1 + 0.06)1               (1 + 0.06)2               (1 + 0.06)3             (1 + 0.06)4 

which is
                   Ž SPPW      Ž SPPW               Ž SPPW              Ž SPPW
P = $1000  | i = .06  | + $1,000  | i = .06 | +  $1000  | i = .06 | +  $1000 | i = .06 |
                 ‘  n = 1 ž                 ‘  n = 2 ž               ‘  n = 3 ž              ‘  n = 4ž

or its equivalent
  P = $1000 (1 +0.06)4 - 1
                0.06(1 + 0.06)4

   = $1000 (3.465) = $3,465, which is said to be the present
value of a 4-year stream of $1000 amounts. The factor, 3.465, is called the
Òuniform series present worthÓ factor for n = 4, i =0.06 (see Table 2, next slide).