         }
         do {
             let a = NDArray<Double>(shape: [2, 2], elements: [1, 2, 3, 4])
-            let b = NDArray<Double>(shape: [2, 2], elements: [-1, 0, 1, 0])
+            let b = NDArray<Double>(shape: [2, 2], elements: [-1, 2, 6, 1])
             XCTAssertEqual(a / b, NDArray(shape: [2, 2], elements: [-1, 1, 0.5, 4]))
         }
     }

        }
        do {
            let a = NDArray<Double>(shape: [2, 2], elements: [1, 2, 3, 4])
            let b = NDArray<Double>(shape: [2, 2], elements: [-1, 0, 1, 0])
            XCTAssertEqual(a * b, NDArray(shape: [2, 2], elements: [-1, 0, 6, 4]))
        }
    }

        do {
            let a = NDArray<Double>(shape: [2, 2], elements: [1, 2, 3, 4])
            XCTAssertEqual(a / 2, NDArray(shape: [2, 2], elements: [0.5, 1.0, 1.5, 2.0]))
            XCTAssertEqualWithAccuracy(2 / a, NDArray(shape: [2, 2], elements: [2.0, 1.0, 2.0/3.0, 0.5]),
                                       accuracy: 1e-10)
        }
        
        // NDArray and NDArray
