diff --git a/javascript/chronometer.js b/javascript/chronometer.js
index 7a13496..aeef306 100644
--- a/javascript/chronometer.js
+++ b/javascript/chronometer.js
@@ -1,34 +1,61 @@
 class Chronometer {
   constructor() {
     // ... your code goes here
+    this.currentTime = 0;
+    this.intervalId = null;
   }
 
   start(callback) {
     // ... your code goes here
+    this.intervalId = setInterval(() => {
+      this.currentTime++;
+
+      if (callback) {
+        callback();
+      }
+    }, 1000);
   }
 
   getMinutes() {
     // ... your code goes here
+    const minutes = Math.floor(this.currentTime / 60);
+    return minutes;
   }
 
   getSeconds() {
     // ... your code goes here
+    const seconds = this.currentTime % 60;
+    return seconds;
   }
 
   computeTwoDigitNumber(value) {
     // ... your code goes here
+    var formattedNumber = ('0' + value).slice(-2);
+    const val = formattedNumber.toString();
+    return val;
   }
 
   stop() {
     // ... your code goes here
+    clearInterval(this.intervalId);
   }
 
   reset() {
     // ... your code goes here
+    this.currentTime = 0;
   }
 
   split() {
     // ... your code goes here
+    const minute = this.getMinutes();
+    const minVal = this.computeTwoDigitNumber(minute);
+
+    const second = this.getSeconds();
+    const secVal = this.computeTwoDigitNumber(second);
+
+    const formattedTime = `${minVal}:${secVal}`;
+
+    return formattedTime;
   }
 }
 
diff --git a/javascript/index.js b/javascript/index.js
index fb3a43a..408c99f 100644
--- a/javascript/index.js
+++ b/javascript/index.js
@@ -15,51 +15,105 @@ const splitsElement = document.getElementById('splits');
 
 function printTime() {
   // ... your code goes here
+  printMinutes();
+  printSeconds();
+  printMilliseconds();
 }
 
 function printMinutes() {
   // ... your code goes here
+  const minutes = chronometer.getMinutes();
+  const minutesVal = chronometer.computeTwoDigitNumber(minutes);
+
+  minDecElement.innerHTML = minutesVal[0];
+  minDecElement.innerHTML = minutesVal[1];
 }
 
 function printSeconds() {
   // ... your code goes here
+  const seconds = chronometer.getSeconds();
+  const secondsVal = chronometer.computeTwoDigitNumber(seconds);
+
+  secDecElement.innerHTML = secondsVal[0];
+  secUniElement.innerHTML = secondsVal[1];
 }
 
 // ==> BONUS
 function printMilliseconds() {
   // ... your code goes here
+
 }
 
 function printSplit() {
   // ... your code goes here
+  const TimeofSplit = chronometer.split();
+  const newSplit = document.createElement('li');
+
+  newSplit.innerHTML = TimeofSplit;
+  splitsElement.appendChild(newSplit);
 }
 
 function clearSplits() {
   // ... your code goes here
+  splitsElement.innerHTML = '';
 }
 
 function setStopBtn() {
   // ... your code goes here
+  btnLeftElement.innerHTML = 'STOP';
+  btnLeftElement.className = 'btn stop';
 }
 
 function setSplitBtn() {
   // ... your code goes here
+  if (btnLeftElement.className.includes('stop')) {
+    btnRightElement.innerHTML = 'SPLIT';
+    btnRightElement.className = 'btn split';
+  } else {
+    btnRightElement.innerHTML = 'RESET';
+    btnRightElement.className = 'btn reset';
+  }
 }
 
 function setStartBtn() {
   // ... your code goes here
+  btnLeftElement.innerHTML = 'START';
+  btnLeftElement.className = 'btn start';
 }
 
 function setResetBtn() {
   // ... your code goes here
+  if (btnLeftElement.className.includes('stop')) {
+    btnRightElement.innerHTML = 'SPLIT';
+    btnRightElement.className = 'btn split';
+  } else {
+    btnRightElement.innerHTML = 'RESET';
+    btnRightElement.className = 'btn reset';
+  }
 }
 
 // Start/Stop Button
 btnLeftElement.addEventListener('click', () => {
   // ... your code goes here
+  if (btnLeftElement.className.includes('start')) {
+    setStopBtn();
+    setSplitBtn();
+    chronometer.start(printTime);
+  } else {
+    setStartBtn();
+    setResetBtn();
+    chronometer.stop();
+  }
 });
 
 // Reset/Split Button
 btnRightElement.addEventListener('click', () => {
   // ... your code goes here
+  if (btnRightElement.className.includes('reset')) {
+    chronometer.reset();
+    printTime();
+    clearSplits();
+  } else {
+    printSplit();
+  }
 });