diff --git a/BasicCalculator/index.html b/BasicCalculator/index.html
index e8fa87a4..20e9ad8d 100644
--- a/BasicCalculator/index.html
+++ b/BasicCalculator/index.html
@@ -4,7 +4,7 @@
     <meta charset="UTF-8">
     <meta http-equiv="X-UA-Compatible" content="IE=edge">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <link rel="stylesheet" href="/style.css"/>
+    <link rel="stylesheet" href="style.css"/>
     <title>Calculator</title>
 </head>
 <body>    
@@ -24,6 +24,7 @@
                 <input type="button" value="8" class="nums" onclick='getkey("8")' id="num-8">
                 <input type="button" value="9" class="nums" onclick='getkey("9")' id="num-9">
                 <input type="button" value="0" class="nums" onclick='getkey("0")' id="num-0">
+                <input type="button" value="." class="nums" onclick='getDecimal()' id="num-decimal">
 
             </div>
             <div class="btn-oprs">
@@ -38,6 +39,6 @@
             </div>
         </form>
     </div>
-    <script type = "text/javascript" src="/script.js"></script>
+    <script type = "text/javascript" src="script.js"></script>
 </body>
 </html>
\ No newline at end of file
diff --git a/BasicCalculator/script.js b/BasicCalculator/script.js
index 947e5f6b..9763cc0a 100644
--- a/BasicCalculator/script.js
+++ b/BasicCalculator/script.js
@@ -7,28 +7,30 @@ const getkey = (key)=>{
                 if(key == '='){
                         output_win.innerHTML = "INVALID OPERATION";
                         expression = "";
+                        firstVal = true;
                 }
-
                 else{
                         expression = key;
-                        output_win.innerHTML += key;
+                        output_win.innerHTML = key; 
                         firstVal = false;
                 }
         }
         else{
                 if(key != '='){
                         expression += key;
-                        output_win.innerHTML += key;
+                        output_win.innerHTML = expression; 
                 }        
                 else{
                         try{
-
-                                output_win.innerHTML = eval(expression).toString();                
+                                let result = eval(expression).toString();
+                                output_win.innerHTML = result;
+                                expression = result; 
+                                firstVal = false; 
                         }
-
                         catch(err){
                                 output_win.innerHTML = "INVALID OPERATION";
                                 expression = "";
+                                firstVal = true;
                         }
                 }
         }
@@ -37,15 +39,48 @@ const getkey = (key)=>{
 const getClr = ()=>{
         output_win.innerHTML = "";
         expression = "";
+        firstVal = true;
 }
 
 const leftPar = ()=>{
         lp =  document.getElementById('btn-leftPar').value;
-        output_win.innerHTML += lp;
-        expression += lp;
+        if(firstVal){
+                expression = lp;
+                output_win.innerHTML = lp;
+                firstVal = false;
+        } else {
+                expression += lp;
+                output_win.innerHTML = expression;
+        }
 }
 const rightPar = ()=>{
         rp =  document.getElementById('btn-rightPar').value;
-        output_win.innerHTML += rp;
-        expression += rp;
+        if(firstVal){
+                expression = rp;
+                output_win.innerHTML = rp;
+                firstVal = false;
+        } else {
+                expression += rp;
+                output_win.innerHTML = expression;
+        }
 }
+
+const getDecimal = ()=>{
+        if(expression == "" || expression == undefined || firstVal){
+                expression = "0.";
+                output_win.innerHTML = "0.";
+                firstVal = false;
+        }
+        else{
+                
+                let lastOperatorIndex = Math.max(expression.lastIndexOf('+'), expression.lastIndexOf('-'), 
+                                               expression.lastIndexOf('*'), expression.lastIndexOf('/'),
+                                               expression.lastIndexOf('('));
+                let currentNumber = expression.substring(lastOperatorIndex + 1);
+                
+                if(!currentNumber.includes('.')){
+                        expression += ".";
+                        output_win.innerHTML = expression;
+                }
+        }
+}
\ No newline at end of file
diff --git a/BasicCalculator/style.css b/BasicCalculator/style.css
index ce78b69c..f561d68f 100644
--- a/BasicCalculator/style.css
+++ b/BasicCalculator/style.css
@@ -56,7 +56,7 @@
     width: 50%;
     background-color:azure;
     display:grid;
-    grid-template-columns: 50% 50%;
+    grid-template-columns: 33.33% 33.33% 33.33%;
     place-items:center;
     box-sizing: border-box;
     border-radius: 10px;
