dissenting.
I dissent.
An award of prejudgment interest is not appropriate in this case.
The facts in this case show that the defendants did not breach a contract to pay a definite sum of money, or to render a performance the money value of which is stated in the contract or is ascertainable by mathematical calculation from a standard fixed in the contract or from market prices of the subject matter. See Restatement of Contracts § 337(a) (1932). The defendants are not chargeable with interest on a sum unless the amount is fixed by the contract or the defendants could have determined the amount with reasonable certainty to make a proper tender. Restatement (Second) of Contracts § 354 comment c (1981). The trial court found agreements between the parties and the terms of those agree: ments based on written estimates of costs and expenses, correspondence, verbal understandings, and the actions and conduct of the parties. The terms of the agreements and the amounts due under those terms were not determinable prior to the trial court’s construction of the agreements. Thus, the amounts owed by the defendants were not ascertainable by mathematical calculation prior to the judgment of the trial court. See Kennedy v. Moutray, 91 N.M. 205, 572 P.2d 933 (1977).
This being the case, an award of prejudgment interest then becomes a matter of the trial court’s discretion. See Restatement of Contracts § 337(b); Restatement (Second) of Contracts % 354(2). The trial court properly exercised its discretion by refusing to award prejudgment interest. See O’Meara v. Commercial Insurance Co., 71 N.M. 145, 376 P.2d 486 (1962). As we have said many times, we will not review the exercise of a trial court’s discretion absent an abuse of discretion. Edington v. Alba, 74 N.M. 263, 392 P.2d 675 (1964). There is no abuse of discretion in this case.
I would affirm the trial court.