diff --git a/Calculators/Basic-Calculator/index.html b/Calculators/Basic-Calculator/index.html
index 10a1abca9..a7bb24bde 100644
--- a/Calculators/Basic-Calculator/index.html
+++ b/Calculators/Basic-Calculator/index.html
@@ -20,34 +20,37 @@
             <span class="num clear" onclick="calc.txt.value = '' "><i>C</i></span>
             <span class="num" onclick="calc.txt.value += '(' "><i>(</i></span>
             <span class="num" onclick="calc.txt.value += ')' "><i>)</i></span>
-            <span class="num" onclick="calc.txt.value += '/' "><i>/</i></span>
+
+            <span class="num" onclick="divide()"><i>/</i></span>
+           
             <span class="num clear-one cle" onclick="clearOne()"><i>CE</i></span>
+
             <span class="num" onclick="calc.txt.value += '7' "><i>7</i></span>
             <span class="num" onclick="calc.txt.value += '8' "><i>8</i></span>
             <span class="num" onclick="calc.txt.value += '9' "><i>9</i></span>
-            <span class="num" onclick="calc.txt.value += '+' "><i>+</i></span>
-            <span class="num" onclick="calc.txt.value += '*' "><i>*</i></span>
-            <span class="num" onclick="calc.txt.value += '-' "><i>-</i></span>
+            <span class="num" onclick="add() "><i>+</i></span>
+            <span class="num" onclick="multiply() "><i>*</i></span>
+            <span class="num" onclick="subtract()"><i>-</i></span>
             <span class="num" onclick="calc.txt.value += '4' "><i>4</i></span>
             <span class="num" onclick="calc.txt.value += '5' "><i>5</i></span>
             <span class="num" onclick="calc.txt.value += '6' "><i>6</i></span>
-            <span class="num" onclick="calc.txt.value += 'Math.sqrt(' "><i>√</i></span>
-            <span class="num" onclick="calc.txt.value += '%' "><i>%</i></span>
+            <span class="num" onclick="squareRoot()"><i>√</i></span>
+            <span class="num" onclick="modulus()"><i>%</i></span>
             <span class="num point" onclick="point()"><i>.</i></span>
             <span class="num" onclick="calc.txt.value += '1' "><i>1</i></span>
             <span class="num" onclick="calc.txt.value += '2' "><i>2</i></span>
             <span class="num" onclick="calc.txt.value += '3' "><i>3</i></span>
-            <span class="num" onclick="calc.txt.value += 'Math.sin(' "><i>sin</i></span>
-            <span class="num" onclick="calc.txt.value += 'Math.cos(' "><i>cos</i></span>
+            <span class="num" onclick="sine()"><i>sin</i></span>
+            <span class="num" onclick="cosine()"><i>cos</i></span>
 
             <span class="num result-give equal cle"
                 onclick="document.calc.txt.value=eval(calc.txt.value)"><i>=</i></span>
 
             <span class="num" onclick="calc.txt.value += ',' "><i>,</i></span>
             <span class="num" onclick="calc.txt.value += '0' "><i>0</i></span>
-            <span class="num" onclick="calc.txt.value += 'Math.pow(' "><i>^</i></span>
-            <span class="num" onclick="calc.txt.value += 'Math.exp(' "><i>exp</i></span>
-            <span class="num" onclick="calc.txt.value += 'Math.log10(' "><i>log</i></span>
+            <span class="num" onclick="power()"><i>^</i></span>
+            <span class="num" onclick="exponent()"><i>exp</i></span>
+            <span class="num" onclick="logarithm()"><i>log</i></span>
         </form>
     </div>
     <script src="script.js"></script>
diff --git a/Calculators/Basic-Calculator/script.js b/Calculators/Basic-Calculator/script.js
index e301e0360..f91f5cb98 100644
--- a/Calculators/Basic-Calculator/script.js
+++ b/Calculators/Basic-Calculator/script.js
@@ -99,8 +99,22 @@ document.addEventListener("keydown", function (event) {
             point();
         }
         else {
-            event.preventDefault();
-            document.getElementById("display").value += event.key;
+            if(event.key==="/" || event.key==="*" || event.key==="+" || event.key==="-" || event.key==="%" || event.key==="^"){
+                //prevent the default behaviour of event
+                event.preventDefault();
+                let currentValue = display.value;
+                let lastChar= currentValue.charAt(currentValue.length-1);
+
+                if(lastChar === "+" || lastChar === "-" || lastChar === "*" || lastChar === "/" || lastChar === "%" || lastChar === "^"){
+                    //if last character is operator, remove it
+                    currentValue=currentValue.substring(0, currentValue.length-1);
+                }
+                //append new operator
+                display.value = currentValue+event.key;
+            }else {
+                event.preventDefault();
+                document.getElementById("display").value += event.key;
+            }                  
         }
     } else if (event.key === "Enter") {
         event.preventDefault();
@@ -166,4 +180,110 @@ function point() {
             return;
         }
     }
-};
\ No newline at end of file
+
+};
+
+
+function add() {
+    let currentValue = calc.txt.value;
+    // Check if the last character is an operator
+    let lastChar = currentValue.charAt(currentValue.length - 1);
+    if (lastChar === "+" || lastChar === "-" || lastChar === "*" || lastChar === "/" || lastChar === "%" || lastChar === "^") {
+        // If the last character is an operator, replace it with the new one
+        currentValue = currentValue.substring(0, currentValue.length - 1);
+    }
+    // Append the "+" operator
+    calc.txt.value = currentValue + "+";
+}
+
+function subtract() {
+    let currentValue = calc.txt.value;
+    let lastChar = currentValue.charAt(currentValue.length - 1);
+    if (lastChar === "+" || lastChar === "-" || lastChar === "*" || lastChar === "/" || lastChar === "%" || lastChar === "^") {
+        currentValue = currentValue.substring(0, currentValue.length - 1);
+    }
+    calc.txt.value = currentValue + "-";
+}
+
+function multiply() {
+    let currentValue = calc.txt.value;
+    let lastChar = currentValue.charAt(currentValue.length - 1);
+    if (lastChar === "+" || lastChar === "-" || lastChar === "*" || lastChar === "/" || lastChar === "%" || lastChar === "^") {
+        currentValue = currentValue.substring(0, currentValue.length - 1);
+    }
+    calc.txt.value = currentValue + "*";
+}
+
+function divide() {
+    let currentValue = calc.txt.value;
+    let lastChar = currentValue.charAt(currentValue.length - 1);
+    if (lastChar === "+" || lastChar === "-" || lastChar === "*" || lastChar === "/" || lastChar === "%" || lastChar === "^") {
+        currentValue = currentValue.substring(0, currentValue.length - 1);
+    }
+    calc.txt.value = currentValue + "/";
+}
+
+function modulus() {
+    let currentValue = calc.txt.value;
+    let lastChar = currentValue.charAt(currentValue.length - 1);
+    if (lastChar === "+" || lastChar === "-" || lastChar === "*" || lastChar === "/" || lastChar === "%" || lastChar === "^") {
+        currentValue = currentValue.substring(0, currentValue.length - 1);
+    }
+    calc.txt.value = currentValue + "%";
+}
+
+function power() {
+    let currentValue = calc.txt.value;
+    let lastChar = currentValue.charAt(currentValue.length - 1);
+    if (lastChar === "+" || lastChar === "-" || lastChar === "*" || lastChar === "/" || lastChar === "%" || lastChar === "^") {
+        currentValue = currentValue.substring(0, currentValue.length - 1);
+    }
+    calc.txt.value = currentValue + "^";
+}
+
+function logarithm() {
+    let currentValue = calc.txt.value;
+    let lastChar = currentValue.charAt(currentValue.length - 1);
+    if (lastChar === "+" || lastChar === "-" || lastChar === "*" || lastChar === "/" || lastChar === "%" || lastChar === "^") {
+        currentValue = currentValue.substring(0, currentValue.length - 1);
+    }
+    calc.txt.value = currentValue + "Math.log10(";
+}
+
+function exponent() {
+    let currentValue = calc.txt.value;
+    let lastChar = currentValue.charAt(currentValue.length - 1);
+    if (lastChar === "+" || lastChar === "-" || lastChar === "*" || lastChar === "/" || lastChar === "%" || lastChar === "^") {
+        currentValue = currentValue.substring(0, currentValue.length - 1);
+    }
+    calc.txt.value = currentValue + "Math.exp(";
+}
+
+function squareRoot() {
+    let currentValue = calc.txt.value;
+    let lastChar = currentValue.charAt(currentValue.length - 1);
+    if (lastChar === "+" || lastChar === "-" || lastChar === "*" || lastChar === "/" || lastChar === "%" || lastChar === "^") {
+        currentValue = currentValue.substring(0, currentValue.length - 1);
+    }
+    calc.txt.value = currentValue + "Math.sqrt(";
+}
+
+function sine() {
+    let currentValue = calc.txt.value;
+    let lastChar = currentValue.charAt(currentValue.length - 1);
+    if (lastChar === "+" || lastChar === "-" || lastChar === "*" || lastChar === "/" || lastChar === "%" || lastChar === "^") {
+        currentValue = currentValue.substring(0, currentValue.length - 1);
+    }
+    calc.txt.value = currentValue + "Math.sin(";
+}
+
+function cosine() {
+    let currentValue = calc.txt.value;
+    let lastChar = currentValue.charAt(currentValue.length - 1);
+    if (lastChar === "+" || lastChar === "-" || lastChar === "*" || lastChar === "/" || lastChar === "%" || lastChar === "^") {
+        currentValue = currentValue.substring(0, currentValue.length - 1);
+    }
+    calc.txt.value = currentValue + "Math.cos(";
+}
+
+