My score is 0 no matter what and I can't figure out why. Can anyone help?

var numberCorrect = 0;

var question1 = prompt("Who was the first African American president?");
if (question1.toUpperCase == "BARACK OBAMA" || question1.toUpperCase == "OBAMA" || question1.toUpperCase == "BARACK") {
    alert("#1 is correct!");
    numberCorrect += 1;
}

var question2 = prompt("Who wrote the original communist manifesto?");
if (question2.toUpperCase == "KARL MARX" || question2.toUpperCase == "MARX") {
    alert("#2 is correct!");
    numberCorrect += 1;
}

var question3 = prompt("What city has the largest population?");
if (question3.toUpperCase == "TOKYO") {
    alert("#3 is correct!");
    numberCorrect += 1;
}

var question4 = prompt("What is the largest planet in the solar system?");
if (question4.toUpperCase == "JUPITER") {
    alert("#4 is correct!");
    numberCorrect += 1;
}

var question5 = prompt("One tablespoon is equal to how many teaspoons?");
if (question5.toUpperCase == "THREE" || parseInt(question5) === 3) {
    alert("#5 is correct!");
    numberCorrect += 1;
}

alert("You got " + numberCorrect + " out of 5 questions right!");