We raise the following general question regarding a ring graded by a group: "If P is a ring-theoretic property, how does one define the graded version P gr of the property P in a meaningful way?". Some properties of rings have straightforward and unambiguous generalizations to their graded versions and these generalizations satisfy all the matching properties of the nongraded case. If P is either being unit-regular, having stable range 1 or being directly finite, that is not the case. The first half of the paper addresses this issue. Searching for appropriate generalizations, we consider graded versions of cancellation, internal cancellation, substitution, and module-theoretic direct finiteness.In the second half of the paper, we turn to Leavitt path algebras. For Leavitt path algebras of finite graphs, we characterize graded unit-regularity and other cancellation properties in terms of the graph properties. Then we provide a complete description of graded matrix algebras over a trivially graded field which are graded isomorphic to Leavitt path algebras. As a consequence, we show that there are graded corners of Leavitt path algebras which are not graded isomorphic to Leavitt path algebras. This contrasts a recent result stating that every corner of a Leavitt path algebra of a finite graph is isomorphic to another Leavitt path algebra. If R is a finite direct sum of graded matricial algebras over a trivially graded field and over naturally graded fields of Laurent polynomials, we also present conditions under which R can be realized as a Leavitt path algebra.