I did purchase a food scale, and did the actual weighing of the ingredients instead of mathematical calculations (3lbs=48 oz=6cups) and 3 pounds of powder mix was equivalent to EIGHT cups.
For anyone that wants to use the 50# Pillsbury bakers plus Devils Food mix for small amounts of cake (this made 28 cupcakes)
1. 4 cups of powdered mix (should weigh one and a half pounds);
add 6oz. water; mix on low one minute, scrape.
2. Then add 5 more ounces of water over one minute, then mix on medium for 2 minutes; scrape.
3. Add another five ounces of water, along with three ounces of oil, mix on low two minutes; scrape.
The above made 28 cupcakes.
I also measured the water on my scale, but it came out to the same as 5 ounces on my measuring cup....so if you have a crisp line on yours, you should be fine measuring instead of weighing.
I hope this helps others!!!!