JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.0.0-beta1/jquery.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/bacon.js/0.7.83/Bacon.js"></script>
<button id="sub">-</button>
<span id="count"></span>
<button id="add">+</button>

JavaScript

const render = (model) => $('#count').text(model);

const add$ = $('#add').asEventStream('click').map(1);
const sub$ = $('#sub').asEventStream('click').map(-1);
const sum = (x, y) => x + y;

const model = add$.merge(sub$).scan(0, sum);
model.onValue(render)