Potrzebie
en.wikipedia.org
en.wikipedia.org
also the Google calculator example:
potrzeba is a neutral form of a noun, meaning `a need.
`potrzebie` is a inflected form, dativus i guess.
example of usage: `trzeba pomagać ludziom w potrzebie' ~> `one needs to help people in need`
[w kim?/w czym? w potrzebie] is locutive.
[komu?/czemu? tej potrzebie] would be dative.