(2) For the purpose of determining the shares of the beneficiaries of either a residuary gift or a class gift under a trust, the value of all advancements made by the settlor to beneficiaries of such gift shall be added to the value of the total property distributed pursuant to the gift, the sum then divided among all beneficiaries of the gift, and the value of the advancement then deducted from the share of the beneficiary to whom the advancement was made. [Formerly 128.397]