Measuring abv when adding sugar during fermentation

[TheMerkle]

So as the title suggests, I've started a brew and I intend to continually feed it dextrose throughout fermentation. As far as figuring ABV, could I just add the amount of dextrose used to the beersmith recipe to determine my "adjusted OG" and compare that to my actual FG for ABV?

 

[Mainer]

I've read that a pound of sugar per gallon will increase your starting gravity by .046. Thus, an ounce per gallon would result in an adjustment of .002875. An ounce in five gallons .000575. I leave any remaining calculations to you.