changes made

app.js

@@ -1,2 +1,7 @@
 // Iteration 1: Making the play button in the index.html functional.
 // Description: When the play button is clicked the game.html page should be opened
+const play = document.getElementById("play-button");
+
+play.onclick = () => {
+  location.href = "./game.html";
+};

game.js

@@ -1,11 +1,135 @@
 // Iteration 2: Generating two random numbers (0 to 100) and displaying the same in the game.html
+var number1 = Math.round(Math.random() * 100);
+const number1box = document.getElementById("number1");
+
+var number2 = Math.round(Math.random() * 100);
+const number2box = document.getElementById("number2");
 
 // Iteration 3: Creating variables required to make the game functional
+var operator;
+var score = 0;
+const plus = document.getElementById("plus");
+const minus = document.getElementById("minus");
+const mul = document.getElementById("mul");
+const divide = document.getElementById("divide");
+const modulus = document.getElementById("modulus");
 
-// Iteration 4: Creating a variable for number 3 and a variable for storing the html element with the Id "number3"
 
+// Iteration 4: Creating a variable for number 3 and a variable for storing the html element with the Id "number3"
+var number3box = document.getElementById("number3");
+var number3;
 // Iteration 5: Creating a randomise function to make the game functional
-
+function randomise() {
+    number1 = Math.round(Math.random() * 100);
+    number2 = Math.round(Math.random() * 100);
+
+    if (number1 < number2) {
+      var extra = number1;
+      number1 = number2;
+      number2 = extra;
+    }
+
+    operator = Math.round(Math.random() * 5);
+    switch (operator) {
+      case 1:
+        number3 = number1 + number2;
+        break;
+
+      case 2:
+        number3 = number1 - number2;
+        break;
+
+      case 3:
+        number3 = number1 * number2;
+        break;
+
+      case 4:
+        number3 = Math.floor(number1 / number2);
+        break;
+
+      case 5:
+        number3 = number1 % number2;
+        break;
+
+      case 0:
+        randomise();
+    }
+
+    number1box.innerHTML = number1;
+    number2box.innerHTML = number2;
+    number3box.innerHTML = number3;
+
+    console.log(number1 + " " + number2 + " " + number3 + " " + operator);
+  }
+
+  randomise();
 // Iteration 6: Making the Operators (button) functional
-
+plus.onclick = () => {
+    if (number1 + number2 === number3) {
+      score++;
+      randomise();
+      resetTime(timerId);
+    } else {
+      location.href = "gameover.html?score=" + score;
+    }
+  };
+minus.onclick = () => {
+    if (number1 - number2 === number3) {
+      score++;
+      randomise();
+      resetTime(timerId);
+    } else {
+      location.href = "gameover.html?score=" + score;
+    }
+  };
+
+mul.onclick = () => {
+    if (number1 * number2 === number3) {
+      score++;
+      randomise();
+      resetTime(timerId);
+    } else {
+      location.href = "gameover.html?score=" + score;
+    }
+  };
+
+divide.onclick = () => {
+    if (Math.floor(number1 / number2) === number3) {
+      score++;
+      randomise();
+      resetTime(timerId);
+    } else {
+      location.href = "gameover.html?score=" + score;
+    }
+  };
+
+modulus.onclick = () => {
+    if (number1 % number2 === number3) {
+      score++;
+      randomise();
+      resetTime(timerId);
+    } else {
+      location.href = "gameover.html?score=" + score;
+    }
+  }; 
+
 // Iteration 7: Making Timer functional
+var time = 20;
+var timerId;
+
+function startTimer() {
+  time = 20;
+  timer.innerHTML = time;
+  timerId = setInterval(() => {
+    time--;
+    if (time == 0) location.href = "./gameover.html?score=" + score;
+    timer.innerHTML = time;
+  }, 1000);
+}
+
+function resetTime(intervalId) {
+  clearInterval(intervalId);
+  startTimer();
+}
+
+startTimer();

score.js

@@ -1 +1,13 @@
 // Iteration 8: Making scoreboard functional
+var url = new URLSearchParams(window.location.search);
+console.log(url);
+var score = url.get("score");
+
+var scoreBoard = document.getElementById("score-board");
+
+var playAgainButton = document.getElementById("play-again-button");
+
+scoreBoard.innerHTML = score;
+playAgainButton.onclick = (evt) => {
+  location.href = "./game.html";
+};