delivered the opinion oe the Court.
This was a bill in equity by appellant to reform a contract in writing whereby he agreed to pay to appellee $1,150 to excavate and construct a certain land drain or ditch. The theory of the bill was that a mutual mistake was made by thé parties growing out of an erroneous computation of the cost of the work at the rate of 7£ cents per cubic yard.
The case was referred to the master in chancery for proofs and findings. The master found'there was no mistake and the court sustained the finding and dismissed the bill.
A clear preponderance of the evidence shows that the price agreed upon for the construction of the ditch was 7-J- cents per yard and that the whole number of cubic yards in it was 7,666.
In making the computation appellant and appellee erroneously found that the ditch would contain 15,333£ yards. The cost of excavating that number of yards at the rate of 7$- cents per yard would be $1,150, and when the contract was drawn that amount was inserted as the contract price for construction. That a mistake was made, is quite clear, not in writing in the instrument the words “ one thousand one hundred and fifty dollars,” because both parties knew _ the contract contained those words at the time of signing^! but the mistake consisted in the belief that 15,333-J cubic yards of dirt were to be removed when in truth there were only 7,666 yards to be removed.
It matters not that the parties knew they were signing a contract in which the price was fixed at $1,150. The question is not, did the parties know what words they used, but rather do the words used express the real intention of j the parties % . ^
Where it is sought in equity to reform a written instrument the chancellor will look beyond the question of whether the parties signing it knew and understood the exact words employed to the true intentions of the parties when they agreed upon the words. If the instrument does not express the true intention, although there was no slip of the pen or mistake made in merely writing words, the instrument will be reformed. The mistake here consisted solely of an erroneous mathematical calculation, and authority for correcting it is abundant. Hunter v. Bilyeu, 30 Ill. 228; McClosky v. McCormick, 44 Ill. 336; Purvines v. Harrison, 151 Ill. 219.
The contention of appellee that the two ditches were to be constructed at the price of - $1,450, and that separate written contracts were drawn at the request of appellant is not borne out by the proofs. The testimony of appellee on that point is unreasonable and unworthy of belief.
The decree will be reversed and the cause remanded with directions to grant the relief prayed for in the bill.