This seems to work:
var num = 0.01
var add = (num.toFixed(2) + 5) * 10
The basic idea is that it takes the number, tells it to be added to the 1000ths place (so in this case, after the 1), adds the new number in the 1000ths place, then multiplies by 10 to account for the decimal shift.
You could then make a function:
function add(base, add){
return (base.toFixed(2) + add) * 10
}
Which isn't super pretty, but:
add(add(0.01, 5), 7);
Or:
var base = 0.01,
numbers = [5, 7];
for (var i = 0; i < numbers.length; i++){
base = add(base, numbers[i]);
}
alert(base);
Would output 1.57
.