JSFiddle - React, Tailwind, and code Playground

HTML

<select class="count" name="money" id="money">
	<option title="100" value="one">Сто</option>
	<option title="200" value="two">Двести</option>
	<option title="300" value="three">Триста</option>
</select>
<select class="count" name="money2" id="money2">
	<option title="500" value="five">Пятьсот</option>
	<option title="600" value="six">Шестьсот</option>
	<option title="700" value="seven">Семьсот</option>
</select>
<span class="total"></span>

JavaScript

$(document).ready(function(){
	$(".count").change(function () {
		var money = parseInt($('#money option:selected').attr('title'));
		var money2 = parseInt($('#money2 option:selected').attr('title'));
		var total = money + money2;

		$('span.total').text(total);
	});
});