Which subledger value is considered?

While Doing OPM Inventory Reconcilition

For Item -FGARCO2MIX85/15

Inventory valuation of Apr-13 = 2180.585324    (primary qty = 120   &  item cost of  Apr  = 18.17154436 )

Inventory valuation of May-13 = 2297.15475     (primary qty = 127.5 &  item cost of  May  = 18.0169)

from above,

how Subledger value will calculated?

               1)        Inventory movement May 13- Apr13 = 2297.15475- 2180.585324 =    116.5694264

              2)        transacted qty  = 127.5 - 120 = 7.5

                                             = subledger cost = 7.5 * 18.0169 (item cost -May ) =    135.126

So which method of calculation is  correct ?? for reconcilition

I confused ?

Plz guide.