Per Curiam.

Defendant Hospitality Motor Inns, Inc. (now Harley Hotels, Inc.), appeals as of right from an order of summary judgment holding that plaintiffs notice of intention to claim mechanics’ lien was timely served and from a judgment in favor of plaintiff in the amount of $15,389.43 due under the lien.

In August, 1977, Hospitality Motor Inns, Inc., contracted for Russo Ornamental Iron Products, Inc., to provide all labor, materials, equipment and supervision for the installation of metal work at five Hospitality Motor Inns under construction, *252 including one in Lansing, Michigan. On September 27, 1977, Russo subcontracted the work to plaintiff, R & T Sheet Metal, Inc.

On May 6, 1978, plaintiff delivered the necessary materials to the Lansing construction site for work to be done by plaintiff at a later date. Plaintiff commenced work at the Lansing site on June 5, 1978, and completed the project on or around August 15, 1978. Plaintiff filed a notice of intention to claim lien upon defendant on August 29, 1978.

Plaintiff and defendant brought cross-motions for summary judgment on the issue of whether plaintiff’s notice of intention to claim lien was timely served. The trial court granted summary judgment to plaintiff, holding that the notice was timely served and reserving the question of the amount of damages owed. Trial was subsequently held on the question of damages. The court found for plaintiff in the amount of $15,389.43.

Defendant first argues that the trial court incorrectly held that plaintiff’s notice of intention to claim lien was timely served.

The mechanics’ lien statute, MCL 570.1; MSA 26.281, 1 states in pertinent part:

"[A]nd every person who shall be subcontractor, * * * perform any labor or furnish materials * * * to such original or principal contractor * * * in carrying forward or completing any such contract, shall have a lien therefore upon such * * * building * * *: Provided, That any person, firm or corporation furnishing materials or performing labor of any kind entering into the construction of any such building * * * shall within 90 *253 days after furnishing the first of such material or performing the first of such labor * * * serve on the owner * * * or his agent * * * a written notice * * * as will inform the owner * * * that such person, firm or corporation furnishing materials or performing labor will claim a lien upon such premises for any amounts unpaid for such materials so furnished or labor performed * * *.”

The trial court found that the 90-day notice limitation period began to run when the materials were first incorporated into the building, not when they were first delivered to the job site, and, therefore, plaintiffs notice was timely served. We affirm the trial court’s ruling that plaintiffs notice was timely. The grounds for our decision, however, are different than those relied upon by the trial court.

The issue here is one of statutory construction. The notice provision in MCL 570.1; MSA 26.281 states that the notice of intent to claim lien shall be given "within 90 days after furnishing the first of such materials or performing the first of such labor”. (Emphasis added.) In construing this statutory provision, we are governed by traditional rules of construction:

"[I]f the statute is unambiguous on its face, we will avoid further interpretation or construction of its terms. Detroit v Redford Twp, 253 Mich 453; 235 NW 217 (1931). However, if ambiguity exists, it is our duty to give effect to the intention of the Legislature in enacting the statute. Melia v Employment Security Comm, 346 Mich 544; 78 NW2d 273 (1956). To resolve a perceived ambiguity, a court will look to the object of the statute, the evil or mischief which it is designed to remedy, and will apply a reasonable construction which best accomplishes the statute’s purpose. Bennetts v State Employees Retirement Board, 95 Mich App 616; 291 NW2d 147 (1980), Stover v Retirement Board of St Clair Shores, 78 Mich App 409; 260 NW2d 112 (1977). Also, ambiguous statutes will be interpreted as a whole *254 and construed so as to give effect to each provision and to produce an harmonious and consistent result. In re Petition of State Highway Comm, 383 Mich 709; 178 NW2d 923 (1970), People v Miller, 78 Mich App 336; 259 NW2d 877 (1977). Further, specific words in a given statute will be assigned their ordinary meaning unless a different interpretation is indicated. Oshtemo Twp v Kalamazoo, 77 Mich App 33, 39; 257 NW2d 260 (1977), MCL 8.3a; MSA 2.212(1).” Pittsfield Twp v City of Saline, 103 Mich App 99, 104-105; 302 NW2d 608 (1981).

Section 27 of the mechanics’ lien act declares that the act is a remedial statute intended to benefit and protect subcontractors, materialmen, and laborers and should be construed liberally in order to carry out the intent of the Legislature. MCL 570.27; MSA 26.307. Georgia-Pacific Corp v Central Park North Co, 394 Mich 59, 66; 228 NW2d 380 (1975).

The disjunctive "or” recognizes two distinct events which trigger the 90-day limitations period, depending on whether the lien is being claimed for materials or labor. Plaintiffs claim herein is for labor performed. All parties agree that plaintiff had been paid for the materials and their fabrication prior to delivery of the materials to the various job sites. Therefore, upon delivery of the materials to the job sites, plaintiff was not entitled to claim a lien and had absolutely no reason to do so. It was only after plaintiff had completed labor on four of the jobs, and had not been paid for the labor performed on the fifth (Lansing) job site, that plaintiff could and did file a lien claim. To hold, as defendant urges, that plaintiff is precluded from claiming a lien because it did not file notice at a time when it had no right or reason to do so is illogical and violates the act’s remedial purpose.

Plaintiffs lien is claimed solely for labor performed. Since notice was served within 90 days *255 after "performing the first of such labor”, the notice was timely served.

It was undisputed that plaintiff fully performed its contract for the fabrication, production and installation of certain materials at the Lansing construction site. The trial court found that the amount owed to plaintiff was $15,389.43. Defendant claims that insufficient evidence was introduced to establish the amount owed with reasonable certainty. This Court will not set aside the trial court’s finding unless it was clearly erroneous. Detroit Independent Sprinkler Co v Plywood Products Corp, 311 Mich 226, 230; 18 NW2d 387 (1945); Loranger v Citizens Mutual Ins Co, 100 Mich App 681, 684; 300 NW2d 369 (1980).

Plaintiff was required to prove by a preponderance of the evidence the sum claimed owing to a reasonable certainty. Wheelmakers, Inc v Flint, 47 Mich App 434, 442-443; 209 NW2d 444 (1973). Richard Pizem, president of R & T Sheet Metal, testified that he was responsible for reviewing all billings and accounts receivable of plaintiff. The amount due plaintiff was $15,389.43 for field labor performed on the Lansing project. Pizem arrived at this figure by deducting the cost of fabrication and the cost of materials from the undisputed contract price of $21,491. The cost of materials and fabrication were paid to plaintiff in March, 1978, when fabrication for all five projects was completed.

Contrary to defendant’s assertion, plaintiff was not required to produce the invoices to establish the amount owing.

"The best evidence rule is not applicable to require *256 the introduction of books of account and to exclude parol testimony as to the contents thereof where a witness has independent knowledge of the facts stated therein. Insofar as no attempt is made to prove the contents of books of account but to show certain facts independent thereof, such books are not necessarily the only evidence nor the best evidence of the facts, but a party may make out his case as to such facts by the testimony of a witness.” 29 Am Jur 2d, Evidence, § 475, p 533. See also New Jersey Title Guarantee & Trust Co v McGrath, 239 Mich 404, 408; 214 NW 195 (1927).

Once evidence of the amount of indebtedness was offered, the burden was on defendant to establish a defense of payment. Slater v Christenson, 226 Mich 621, 623; 198 NW 224 (1924). Defendant offered no evidence to rebut plaintiff’s claim. Instead, defendant attempted to show that plaintiff had previously claimed four different amounts owing. Plaintiff’s cost sheet, original complaint and the lien account statement stated the amount owing as $21,490. The ledger sheet indicated that $18,094 was owing. The sworn affidavit by Pizem indicated that $15,843.26 was due, and Pizem’s trial testimony stated that $15,389.43 was due and owing.

The trial court based its judgment of $15,389.43 on the uncontroverted testimony of Pizem that all materials had been paid for, but no payment for labor was received. The court found that the $21,-490 figure was not inconsistent as it reflected the undisputed total contract price without subtracting the amounts previously paid by defendant. Furthermore, the ledger sheet failed to note all previous payments, and a clerical error was the cause of the inconsistency between the earlier sworn affidavit and Pizem’s trial testimony. The court’s finding that plaintiff established the amount due with reasonable certainty was not clearly erroneous.

*257 Finally, defendant argues that the trial court erroneously relied on an admission by Richard Colwell, defendant’s employee, that plaintiff was owed for labor on the Lansing project. We disagree. The trial court did not rely on Colwell’s admission to set the figure of the amount owed, but only considered the evidence as an admission by defendant that plaintiff was not paid for labor performed. The court’s findings with reference to the amount due were properly based on the evidence introduced by plaintiff.

Affirmed.

Notes

This statute was repealed and reenacted by 1980 PA 497, § 303, effective March 1,1982.