diff --git a/index.html b/index.html
index 935c09e..1884a88 100644
--- a/index.html
+++ b/index.html
@@ -6,6 +6,7 @@
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title>Calculator</title>
   <link rel="stylesheet" href="style.css">
+  <script type="text/javascript" src="script.js"></script>
 </head>
 
 <body>
@@ -13,30 +14,30 @@
     <div class="display">&nbsp;</div>
     <div class="buttons">
       <div class="row">
-        <button class="number" id="number-7">7</button>
-        <button class="number" id="number-8">8</button>
-        <button class="number" id="number-9">9</button>
+        <button class="number" id="number-7" onclick="pressButton(event)">7</button>
+        <button class="number" id="number-8" onclick="pressButton(event)">8</button>
+        <button class="number" id="number-9" onclick="pressButton(event)">9</button>
       </div>
       <div class="row">
-        <button class="number" id="number-4">4</button>
-        <button class="number" id="number-5">5</button>
-        <button class="number" id="number-6">6</button>
+        <button class="number" id="number-4" onclick="pressButton(event)">4</button>
+        <button class="number" id="number-5" onclick="pressButton(event)">5</button>
+        <button class="number" id="number-6" onclick="pressButton(event)">6</button>
       </div>
       <div class="row">
-        <button class="number" id="number-1">1</button>
-        <button class="number" id="number-2">2</button>
-        <button class="number" id="number-3">3</button>
+        <button class="number" id="number-1" onclick="pressButton(event)">1</button>
+        <button class="number" id="number-2" onclick="pressButton(event)">2</button>
+        <button class="number" id="number-3" onclick="pressButton(event)">3</button>
       </div>
       <div class="row operations">
-        <!-- <button id="add">+</button>
-        <button id="subtract">-</button>
-        <button id="multiply">*</button>
-        <button id="divide">/</button> -->
+        <button id="add" onclick="pressButton(event)">+</button>
+        <button id="subtract" onclick="pressButton(event)">-</button>
+        <button id="multiply" onclick="pressButton(event)">*</button>
+        <button id="divide" onclick="pressButton(event)">/</button>
       </div>
       <div class="row last-row">
-        <button id="clear">C</button>
-        <button class="number" id="number-0">0</button>
-        <button id="equal">=</button>
+        <button id="clear" onclick="clearScreen()">C</button>
+        <button class="number" id="number-0" onclick="pressButton(event)">0</button>
+        <button id="equal" onclick="calculate()">=</button>
       </div>
     </div>
   </div>
diff --git a/script.js b/script.js
new file mode 100644
index 0000000..a9194f1
--- /dev/null
+++ b/script.js
@@ -0,0 +1,43 @@
+
+exrcise = "";
+
+function pressButton(event) {
+    const screen = document.querySelector(".display");
+    const num = event.target.innerHTML;
+    screen.textContent += num;
+    exrcise += num;
+}
+
+function calculate() {
+    const operators = ["+","-","/","*"];
+    const operator = operators.find(op => exrcise.indexOf(op) > -1);
+    const firstNum = parseInt(exrcise.substring(0,exrcise.indexOf(operator)));
+    const secondNum = parseInt(exrcise.substring(exrcise.indexOf(operator) + 1));
+    let result;
+
+    switch(operator){
+        case "+":
+            result = firstNum + secondNum;
+            break;
+        case "*":
+            result = firstNum * secondNum;
+            break;
+        case "-":
+            result = firstNum - secondNum;
+            break;
+        case "/":
+            result = firstNum / secondNum;
+            break;
+    }
+
+    const screen = document.querySelector(".display");
+    screen.innerHTML = result;
+    exrcise = ""
+}
+
+function clearScreen() {
+    const screen = document.querySelector(".display");
+    screen.innerHTML = "&nbsp;";
+    exrcise = "";
+}
+
