For each separate case below, follow the three$-$step process for adjusting the Accumulated Depreciation account at December $31.$

Step $1$: Determine what the current account balance equals.

Step $2$: Determine what the current account balance should equal.

Step $3$: Record the December $31$ adjusting entry to get from step $1$ to step $2.$

Assume no other adjusting entries are made during the year.