"Chalk it up"...

...comes from keeping score in a game on a blackboard. Metaphorically, it means that some factor has led to some sort of victory or accomplishment. Said sarcastically or derisively, it means that the thing leading to the accomplishment is unearned or to be deplored.

OR...I could just be talking about writing with chalk...everywhere...and anywhere...

...on the driveway, sidewalk, house, screenporch, face, hair, feet...argh.

Chalk it up to...the orneriness of the Sweet Boobahs.

Chalk it up for MomE's lessons on how to use a bucket of lestoil water and a rag...scrub a dub dub.