1. A method for performing floating-point operations on an integrated circuit, comprising: receiving a first floating-point number having a first exponent and a first mantissa, a second floating-point number having a second exponent and a second mantissa, and a third floating-point number having a third exponent and a third mantissa, wherein each of the first, second, and third mantissas has a given precision; expanding the given precision of the first, second, and third mantissas to produce corresponding first, second, and third extended mantissas, wherein the greater number is at least twice as big as the given precision; and producing a sum of the first, second, and third extended mantissas.