Using the metric system, grams would be best.
If using the imperial system, ounces would be fine.
You must first decide WHAT you want to measure about the potatoes - their diameter, circumference, mass, volume, etc. To buy or sell potatoes, the mass (commonly called "weight") is most relevant.
kilograms!
Potatoes are sold by the kilogram.
Oh, dude, you'd totally use pounds to measure a bag of potatoes! Like, unless you're in some fancy country that's all about kilograms or something. But, like, who even knows what a kilogram is, right? Just grab those spuds and throw 'em on the scale, easy peasy.
The same unit as you use to measure any mass. The SI unit for mass is the kilogram.
You would use the unit of measure called "kilograms" to measure the mass of an elephant.
it is use to measure output
The Unit Used To Measure A Train Can Be Kilometer.
what you are trying to measure
Miles
This depends on what unit you are using to measure in. However, area will always be measure in (unit)^2.
scales