             mods.removeAll()
             self.startMeasuring()
             for divisor in divisors {
-                let (div, mod) = fact.divide(divisor)
+                let (div, mod) = fact.divided(by: divisor)
                 divs.append(div)
                 mods.append(mod)
             }

        self.measure {
            fact = BigUInt(1)
            for i in 1...n {
                fact.multiplyInPlaceByDigit(Digit(i))
            }
        }
        checkFactorial(fact: fact, n: n)

    func checkFactorial(fact: BigUInt, n: Int, file: StaticString = #file, line: UInt = #line) {
        var remaining = fact
        for i in 1...n {
            let (div, mod) = remaining.divided(by: BigUInt(i))
            XCTAssertEqual(mod, 0, "for divisor = \(i)", file: file, line: line)
            remaining = div
        }
