What you wrote is clear, but it's a little unnatural. I'd reword it something like this: When reading out a decimal and the integer (to the left of the decimal point) is zero, you do not leave that zero out. And of course, you don't leave out the decimal either. The case is different when you key a number into a calculator. Here, you may just key in .8092 instead of 0.8092. As a side note, sometimes when it's clear to the listener that the leading digit is zero then you can leave it out. Generally though, yes, you mention it so that it's clear.