diff --git a/src/app/courses/services/calculator.service.spec.ts b/src/app/courses/services/calculator.service.spec.ts
index b050edb..8a939c4 100644
--- a/src/app/courses/services/calculator.service.spec.ts
+++ b/src/app/courses/services/calculator.service.spec.ts
@@ -8,12 +8,14 @@ describe('CalculatorService', () => {
     let calculator: CalculatorService,
         loggerSpy: any;
 
-    beforeEach(()=> {
+    beforeEach(() => {
 
         console.log("Calling beforeEach");
 
         loggerSpy = jasmine.createSpyObj('LoggerService', ["log"]);
 
+        // calculator = new CalculatorService(loggerSpy);
+
         TestBed.configureTestingModule({
             providers: [
                 CalculatorService,
@@ -27,11 +29,23 @@ describe('CalculatorService', () => {
 
     it('should add two numbers', () => {
 
+        // const logger = new LoggerService();
+
+        // const logger = jasmine.createSpyObj('LoggerService', ["log"]);
+
+        // spyOn(logger, 'log')
+
+        // const calculator = new CalculatorService(logger);
+
+        const result = calculator.add(2, 2)
+
+        expect(result).toBe(4)
+
         console.log("add test");
 
-        const result = calculator.add(2, 2);
+        // const result = calculator.add(2, 2);
 
-        expect(result).toBe(4);
+        // expect(result).toBe(4);
 
         expect(loggerSpy.log).toHaveBeenCalledTimes(1);
 
@@ -40,11 +54,23 @@ describe('CalculatorService', () => {
 
     it('should subtract two numbers', () => {
 
+        // const calculator = new CalculatorService(new LoggerService());
+
+        // const logger = jasmine.createSpyObj('LoggerService', ["log"]);
+
+        // spyOn(logger, 'log')
+
+        // const calculator = new CalculatorService(logger);
+
+        const result = calculator.subtract(2, 2)
+
+        expect(result).toBe(0, "unexpected subtraction result")
+
         console.log("subtract test");
 
-        const result = calculator.subtract(2, 2);
+        // const result = calculator.subtract(2, 2);
 
-        expect(result).toBe(0, "unexpected subtraction result");
+        // expect(result).toBe(0, "unexpected subtraction result");
 
         expect(loggerSpy.log).toHaveBeenCalledTimes(1);