Calculate the interest at six percent upon the sum to the income of which, or upon the value of the property to the use of which, the person is entitled; multiply this interest by the present value of an annuity of one dollar, as set opposite the person's age in the table, and the product will be the gross value of the life estate of such person therein. The age of such person as indicated by the birthday nearest to the time when said computation is made shall be taken to be the age of such person in making said computation.
§ 442.540, RSMo