Puzzle pieces
A
902
B
457
Id
C08
Job
remove
Reason
Keep count-up as connected check.
Complete source
An imagined puzzle store has 902 pieces and uses 457 once.
Status
Original fictional ordinary practice; teach source/help before any own application.
Title
Puzzle pieces
After own work: adult practice possibility
445 left; 457→500(+43)→900(+400)→902(+2).