         var brainResult = brain.evaluate(using: variableDict)
         XCTAssertEqual(brainResult.result, 3.0)
         XCTAssertNil(variableDict["M"])
-        XCTAssertEqual(brainResult.description, "√(9+M)")
+        XCTAssertEqual(brainResult.description, "√(9 + M)")
 
         //7 →M --> display = 4, M = 7, desc = √(9+M)
         // sets the value of 7 into M
-        brain.setOperand(7)
         variableDict.updateValue(7, forKey:"M")
         brainResult = brain.evaluate(using: variableDict)
         XCTAssertEqual(brainResult.result, 4.0)
         XCTAssertEqual(7, variableDict["M"])
-        XCTAssertEqual(brainResult.description, "√(9+M)")
+        XCTAssertEqual(brainResult.description, "√(9 + M)")
         
         // + 14 = --> display = 18, M = 7, desc ="√(9+M) + 14"
         brain.performOperation("+")

        XCTAssertFalse(brainResult.isPending)
        XCTAssertEqual(brainResult.description, "73")
        
        // 7 + = --> 14, false, "7 + 7 "
        brain.clear()
        brain.setOperand(7)
        brain.performOperation("+")
        brain.performOperation("=")
        brainResult = brain.evaluate()
        XCTAssertEqual(brainResult.result, 14.0)
        XCTAssertFalse(brainResult.isPending)
        XCTAssertEqual(brainResult.description, "7 + 7")
        
        // 4 x π = --> 12.5663706143592, false, "4 + π "
        brain.clear()
        brain.setOperand(4)

    var variableDict = [String:Double]()
    
    //Tests for Assignment 1
    func testCalculatorBrainBasicOperandsHappyPath(){
        brain.clear()
        // 7 + --> 7, true, "7 + "
        brain.setOperand(7)
