JSFiddle - React, Tailwind, and code Playground

HTML

<input id="p1" value="0">
<button id="p11">+1</button>
<button id="p15">+5</button>
<button id="p1t2">*2</button>
<br>
<input id="p2" value="0">
<button id="p21">+1</button>
<button id="p25">+5</button>
<button id="p2t2">*2</button>

JavaScript

gencb = function (fn) {
    return function(id, value){
        return function() {
            $(id).val(fn(parseInt($(id).val()),value));
        };
    };
};

cbplus = gencb(function(a,b) {return a+b;});
cbkrat = gencb(function(a,b) {return a*b;});

$("#p11").click(cbplus("#p1",1));
$("#p15").click(cbplus("#p1",6));
$("#p1t2").click(cbkrat("#p1",2));
$("#p21").click(cbplus("#p2",1));
$("#p25").click(cbplus("#p2",5));
$("#p2t2").click(cbkrat("#p2",2));