/* Some Global variables */ var myCount; // A seconds counter, var mytime; // A timer interval. var inGame; // A Game over flag. var flag; // A win flag. var lose; // A lose flag. var myExerciseDisplay; // The correct exercise. /* Wrong answers */ function loser() { if (inGame === 1) // In game. { lose++; // Wrong answers counter. document.getElementById("res").innerHTML = "Wrong!"; // A "Wrong!"" message. document.getElementById("res").style.visibility = "visible"; // Make the message visiable. } if (lose === 3) // Too many bad tries. { inGame = 0; // game over! clearInterval(myTime); // Stop the clock. document.getElementById("newGame").style.visibility = "visible"; // Allow new round. document.getElementById("res").innerHTML = "Wrong!
Too bad - you lost this round!
The correct exercise was:
" + myExerciseDisplay; // A lose message. document.getElementById("res").style.visibility = "visible"; // Make the message visiable. } } /* The right answer! */ function winner() { inGame = 0; // Game over! flag = 1; // Winner flag is up! if (myCount > 0 && lose < 3) // The clock stoped before time was up and less then 3 wrong clicks. { document.getElementById("newGame").style.visibility = "visible"; // Allow new round. document.getElementById("res").innerHTML = "Great!"; // A winner message. document.getElementById("res").style.visibility = "visible"; // Make the message visiable. } } /* The seconds counter */ function counter() { if (flag === 0 && myCount > 0) // The clock should tick. { myCount--; // One second less. document.getElementById("myCounter").innerHTML = myCount + " Seconds!"; // Show thw clock. } else { clearInterval(myTime); // Stop the clock! if (myCount === 0) // Out of time! { inGame = 0; // Game over! document.getElementById("res").innerHTML = "Sorry. time is up! Better luck next round.
The correct exercise was:
" + myExerciseDisplay; // A lose message. document.getElementById("res").style.visibility = "visible"; // Make the message visiable. document.getElementById("newGame").style.visibility = "visible"; // Allow new round. } } } /* Initialise a new game */ function init() { inGame = 1; // In game. flag = 0; // Winner flag is down. myCount = 30; // Seconds counter reset. lose = 0; // Lose flag is down. let myX = Math.ceil(Math.random()*100); // A random number between 1 and 100 - First operand. let myY = Math.ceil(Math.random()*100); // A random number between 1 and 100 - Second operand. let myOp = Math.ceil(Math.random()*4); // A random operator (+, -, * or /). let myCell = Math.floor(Math.random()*9); // A random table cell number to put the right answer in. let myRes; // The resault. myExerciseDisplay; // The way the exercise is displayed. switch(myOp) // A different operation for each operator. { case 1: // + myRes = myX + myY; // Add the to operands. myExerciseDisplay = myX + " + " + myY + " = " + myRes; // The way the exercise will display. break; // End of + operations. case 2: // - while (myX < myY) // We don't want negative resaults. { myX = Math.ceil(Math.random()*100); // Find another x. myY = Math.ceil(Math.random()*100); // Find another y. } myRes = myX - myY; // Subtract y from x. myExerciseDisplay = myX + " − " + myY + " = " + myRes; // The way the exercise will display. break; // End of - operations. case 3: // * myRes = myX * myY; myExerciseDisplay = myX + " × " + myY + " = " + myRes; // The way the exercise will display. break; // End of * operations. case 4: // / while (myX < myY) // We don't want a division less then 1. { myX = Math.ceil(Math.random()*100); // Find another x. myY = Math.ceil(Math.random()*100); // Find another y. } myRes = Math.floor(myX / myY) + "(" + (myX % myY) + ")"; // Division resault with the remeinder. myExerciseDisplay = myX + " ÷ " + myY + " = " + myRes; // The way the exercise will display. break; // End of / operations. default: // Something wrong happened. alert("An unknown error occurred!"); // Something wrong happened. break; // End of default operations. } // End of operators switch. let cell = document.getElementById("cell" + myCell); // The currecnt cell. cell.innerHTML = myExerciseDisplay; // Display the execercise. cell.onclick = function() {winner()}; // Winner on Click. for (let i = 0; i < 9; i++) // Iterate all the rest of the table. { if (i !== myCell) // Don't overwrite the right answer. { let x = Math.ceil(Math.random()*100); // A random number between 1 and 100 - First operand. let y = Math.ceil(Math.random()*100); // A random number between 1 and 100 - Second operand. let op = Math.ceil(Math.random()*4); // A random operator (+, -, * or /). let res = Math.ceil(Math.random()*1000); // A random number between 1 and 1000 - A false resault. let exerciseDisplay; // The way the exercise is displayed. switch(op) // A different operation for each operator. { case 1: // + res = Math.ceil(Math.random()*200); // A random number between 1 and 200 as a false resault. while (x + y === res) // In case the answer is right... { res = Math.ceil(Math.random()*200); // Find another false answer. } exerciseDisplay = x + " + " + y + " = " + res; // The way the exercise will display. break; // End of + operations. case 2: // - res = Math.ceil(Math.random()*100); // A random number between 1 and 100 as a false resault. while (x < y) // We don't want negative resaults. { x = Math.ceil(Math.random()*100); // Find another x. y = Math.ceil(Math.random()*100); // Find another y. } while (x - y === res) // In case the answer is right... { res = Math.ceil(Math.random()*100); // Find another false answer. } exerciseDisplay = x + " − " + y + " = " + res; // The way the exercise will display. break; // End of - operations. case 3: res = Math.ceil(Math.random()*5000); // A random number between 1 and 5000 as a false resault. while (x * y === res) // In case the answer is right... { res = Math.ceil(Math.random()*5000); // Find another false answer. } exerciseDisplay = x + " × " + y + " = " + res; // The way the exercise will display. break; // End of * operations. case 4: res = Math.ceil(Math.random()*100); // A random number between 1 and 100 as a false resault. while (x < y) { x = Math.ceil(Math.random()*100); // Find another x. y = Math.ceil(Math.random()*100); // Find another y. } while (Math.floor(x / y) === res) // In case the answer is right... { res = Math.ceil(Math.random()*100); // Find another false answer. } exerciseDisplay = x + " ÷ " + y + " = " + res + "(" + (x % y) + ")"; // The way the exercise will display (append the right remeinder). break; // End of / operations. default: // Something wrong happened. alert("An unknown error occurred!"); // Something wrong happened. break; // End of default operations. } // End of operators switch. let cell = document.getElementById("cell" + i); // The currecnt cell. cell.innerHTML = exerciseDisplay; // Display the current false execercise. cell.onclick = function() {loser()}; // Lose on click. } // End current cell } // Go to next cell. } // End function init(). /* Clean & simple */ function main() { init(); // Initialise a new game. document.getElementById("myCounter").innerHTML = ""; // Clear the seconds counter. document.getElementById("res").innerHTML = ""; // Clear messages. document.getElementById("res").style.visibility = "hidden"; // Hide the message. document.getElementById("newGame").style.visibility = "hidden"; // Hide new round. myTime = setInterval(counter, 1000); // Start the timer. }

Nine Squared.html