JSFiddle - React, Tailwind, and code Playground

JavaScript

function getChange() {
    
 var input = prompt('Enter the amount');   
 
 p20 = 0.20;
 p10 = 0.10;
 p5 = 0.05;
 p2 = 0.02;
 p1 = 0.01;
 remaining = 0;
    
 var message = "You want the least possbile change for £"+input+"<br />";
    
 var p20s = (input / p20).toFixed(2);
    
 remaining = (input % p20).toFixed(2);
 var p10s = (remaining / p10).toFixed(2);
    
 remaining = (remaining % p10).toFixed(2);
 var p5s = (remaining / p5).toFixed(2);
    
 remaining = (remaining % p5).toFixed(2);
 var p2s = (remaining / p2).toFixed(2);
    
 remaining = (remaining % p2).toFixed(2);
 var p1s = (remaining / p1).toFixed(2);
    
 
 message += "20 P: &nbsp; "+Math.floor(p20s)+"<br />";
 message += "10 P: &nbsp; "+Math.floor(p10s)+"<br />";
 message += "5 P: &nbsp; "+Math.floor(p5s)+"<br />";
 message += "2 P: &nbsp; "+Math.floor(p2s)+"<br />";
 message += "1 P: &nbsp; "+Math.floor(p1s)+"<br />";
    
    
 document.write(message);
    
}

getChange();