New Appending Problem

buttons.forEach((button) => {
    button.addEventListener('click', () => {
        if (screen.value == 0) {
            screen.value = '';
        }
        else if (counter_buttons === 1) {
            screen.value = '';
            counter_buttons = 1;
            counter_operator = 1;

        }
        screen.value += button.value;

    });
});

operator.forEach((button) => {
    button.addEventListener('click', () => {
        if (counter_buttons === 0) {
            number1 = parseInt(screen.value);

            counter_buttons = 1;
        }
        else if (counter_operator === 1) {
            number2 = parseInt(screen.value);

            counter_operator = 0;
            counter_buttons = 0;
            screen.value = operate(number1, number2, sign);

            number1 = operate(number1, number2, sign);
        }
        sign = button.value;

    });
});