Here is a sample program:
var a = parseFloat("86.69043189999999") + "<br>";
var b = parseFloat("86.79718199999999") + "<br>";
var n = a + b;
document.getElementById("demo").innerHTML = n;
<p id=demo></p>
Both the two variables have exact same decimal point still it's giving two different kind of output:
86.6904319
86.79718199999999
Why such an weird behaviour?