JSFiddle - React, Tailwind, and code Playground

HTML

<p id="myPara">
$200 some $100 content goes $300 here
</p>

JavaScript

var initialText = document.getElementById('myPara').innerText;
var replacedText = initialText.replace(/\$/g, '@');
var numberPattern = /\d+/g;
var numbers = replacedText.match( numberPattern );
for(var i = 0; i < numbers.length; i++){
    var num = numbers[i];
    // your currency conversion here
    var newNum = num * 0.05;
    replacedText = replacedText.replace(num, newNum);
}
alert(replacedText);