diff --git a/SpecRunner.html b/SpecRunner.html
index 0265dc18..544645dd 100644
--- a/SpecRunner.html
+++ b/SpecRunner.html
@@ -12,12 +12,12 @@
     <script src="jasmine/jasmine-2.8.0/boot.js"></script>
 
     <!--  Iterations 1 - 8 -->    
-    <script src="src/chronometer.js"></script>
-    <script src="tests/chronometer.spec.js"></script>
+    <!--<script src="src/chronometer.js"></script>-->
+    <!-- <script src="tests/chronometer.spec.js"></script>-->
 
     <!-- Bonus Iteration 9: Centiseconds -->
-    <!-- <script src="src/chronometer-centiseconds.js"></script> -->
-    <!-- <script src="tests/chronometer-centiseconds.spec.js"></script> -->
+     <script src="src/chronometer-centiseconds.js"></script> 
+     <script src="tests/chronometer-centiseconds.spec.js"></script> 
 
   </head>
 
diff --git a/index.html b/index.html
index 32e914c7..e32a332f 100644
--- a/index.html
+++ b/index.html
@@ -38,10 +38,10 @@ <h3>Splits</h3>
 
 
   <!--  Iterations 1 - 8 -->
-  <script src="src/chronometer.js"></script>
+  <!-- <script src="src/chronometer.js"></script> -->
 
   <!-- Bonus Iteration 9: Centiseconds -->
-  <!-- <script src="src/chronometer-centiseconds.js"></script> -->
+   <script src="src/chronometer-centiseconds.js"></script> 
 
   
   <!--  DOM manipulation logic -->
diff --git a/src/chronometer-centiseconds.js b/src/chronometer-centiseconds.js
index 8337b5b6..e7d0e986 100644
--- a/src/chronometer-centiseconds.js
+++ b/src/chronometer-centiseconds.js
@@ -1,37 +1,52 @@
 class Chronometer {
   constructor() {
-    // ... your code goes here
+    this.currentTime = 0;
+    this.intervalId = null;
   }
 
   start(printTimeCallback) {
-    // ... your code goes here
+    this.intervalId = setInterval(() => {
+      this.currentTime++;
+      if (printTimeCallback) printTimeCallback();
+    }, 10);
+
+    return printTimeCallback;
   }
 
   getMinutes() {
-    // ... your code goes here
+     return Math.floor(this.currentTime / 6000); 
   }
 
   getSeconds() {
-    // ... your code goes here
+    return Math.floor((this.currentTime / 100) % 60)
   }
 
   getCentiseconds() {
-    // ... your code goes here
+     return Math.floor(this.currentTime % 100) 
   }
 
   computeTwoDigitNumber(value) {
-    // ... your code goes here
+    const newValue = value.toString();
+
+    if (newValue.length < 9 || newValue.length >= 0) {
+      let padTime = "0" + newValue;
+      return padTime.slice(-2);
+    }
+
+    return newValue;
   }
 
   stop() {
-    // ... your code goes here
+    return clearInterval(this.intervalId)
   }
 
   reset() {
-    // ... your code goes here
+    return this.currentTime = 0
   }
 
   split() {
-    // ... your code goes here
-  }
+    return `${this.computeTwoDigitNumber(this.getMinutes())}:${this.computeTwoDigitNumber(this.getSeconds())}.${this.computeTwoDigitNumber(this.getCentiseconds())}`;
+
+  
 }
+}
\ No newline at end of file
diff --git a/src/chronometer.js b/src/chronometer.js
index 83c75bd2..e66fa50a 100644
--- a/src/chronometer.js
+++ b/src/chronometer.js
@@ -1,33 +1,53 @@
 class Chronometer {
   constructor() {
-    // ... your code goes here
+    this.currentTime = 0;
+    this.intervalId = null;
   }
 
   start(printTimeCallback) {
-    // ... your code goes here
+    this.intervalId = setInterval(() => {
+      this.currentTime++;
+      if (printTimeCallback) printTimeCallback();
+    }, 1000);
+
+    return printTimeCallback;
   }
 
   getMinutes() {
-    // ... your code goes here
+    return Math.floor(this.currentTime / 60);
   }
 
   getSeconds() {
-    // ... your code goes here
+    return Math.floor(this.currentTime % 60);
   }
-
   computeTwoDigitNumber(value) {
-    // ... your code goes here
+    const newValue = value.toString();
+
+    if (newValue.length < 9 || newValue.length >= 0) {
+      let padTime = "0" + newValue;
+      return padTime.slice(-2);
+    }
+
+    return newValue;
+
+    //  if (value >= 0 || value <= 9){
+    //   const padTime = ('0' + value)
+    //   return padTime.slice(-2).toString()
+    //  }
+    //  const result = value.toString();
+
+    //  return result;
   }
 
   stop() {
-    // ... your code goes here
+    return clearInterval(this.intervalId)
   }
 
   reset() {
-    // ... your code goes here
+    return this.currentTime = 0
   }
 
   split() {
-    // ... your code goes here
+    return `${this.computeTwoDigitNumber(this.getMinutes())}:${this.computeTwoDigitNumber(this.getSeconds())}`
   }
 }