Truncate number to two decimal places without rounding

Question

Suppose I have a value of 15.7784514, I want to display it 15.77 with no rounding.

var num = parseFloat(15.7784514);
document.write(num.toFixed(1)+\"


        

Answer 1

num = 19.66752
f = num.toFixed(3).slice(0,-1)
alert(f)

This will return 19.66