可数名词，因为它的复数是potatoes,加了es,所以它是可数名词。

potato：n.马铃薯;土豆;洋芋

复数： potatoes

I went and bought about six dollars' worth of potato chips

我去买了大约6美元的薯条。

Pierce the skin of the potato with a fork.

用叉子扎破土豆皮。

The fries are made from pellets of pulverised potato.

这些炸土豆是土豆泥球做成的。

Put both vegetables into a bowl and crush with a potato masher.

把这两样蔬菜都放进一个碗里，然后用捣土豆器把它们捣碎。