Munich HBF to MUC

I’m a bit confused about the MVV Streifenkarte U21.

I found a Streifenkarte U21 (10 stripes for €10.20), and the DB app suggests that a trip from München Hbf to Munich Airport requires 7 stripes (zones M–5).

Does this mean that one U21 Streifenkarte is enough for a single trip from München Hbf to MUC Airport, with 3 stripes remaining for future trips?

I’m asking because the regular airport ticket seems to be much more expensive, so I want to make sure I’m not misunderstanding the fare rules.

Has anyone used a Streifenkarte U21 for this route recently?