Floating-point rounding error?

Hmm ..... I don't think the attachment worked so I've pasted the files below. The names of the three javascript files are at the top of the code for each:

//##### plusone.js ##########

// plusone.js

//Increments or decrements a number box by one
//Rolls over between 9 and 0 and outputs a bang

inlets = 1;
outlets = 3;
autowatch = 1;

var x = 0;

function add()
{
if (x == 9) {
x = 0;
outlet(1, "bang");
}
else {
x = x+1;
}
outlet(0, x);
}

function sub()
{
if (x == 0) {
x = 9;
outlet(2, "bang");
}
else {
x = x-1;
}
outlet(0, x);
}

function zero()
{
x = 0;
outlet (0, x);
}

//###### isint.js ######

// isint.js

//tests input to see if it is an int
//if so outputs int otherwise outputs zero

inlets = 1;
outlets = 1;
autowatch = 1;

function text(t)
{
obj = this.patcher.getnamed("tbx_Number");
t = parseInt(t, 10);

if (isNaN(t)) {
t=0;
}

outlet(0, t);
obj.set(t);
}

//###### buildnum.js ######

//buildnum.js
//Joins elements from number boxers to make float

inlets = 1;
outlets = 1;
autowatch = 1;

var whole = 0;
var ten = 0;

function wholenum(a)
{
whole = parseInt(a, 10);
result();
}

function tennum(b)
{
ten = b;
result();
}

function result()
{
var numout = 0;

numout = whole + (ten/10)
outlet (0, numout);
post(numout);
post();
}