Or, rather, on how they don’t work.
Rule number one:
If you insist on using a check to pay at the grocery store, and especially if you are still living in the early half of the 20th century and have ignored the availability of duplicate checks that enable you to NOT stop everything to enter your check in the register and do the flippin’ math, here’s a little tip for you: MOVE ON, do your math somewhere else, and let the next person in line pay for their items. Do NOT make them wait for you to figure out how to borrow one from the tens’ column.
Rule number two:
Similar to rule one, if you are at the drive-through window at the bank, where you have already been sitting for so long you have single-handedly destroyed the remainder of the ozone layer with your car exhaust (What are you doing, anyway? Asking the teller to list the serial numbers of every dollar you’ve ever deposited?!?) do NOT remain next to the pneumatic tube while you count and put away your cash, reorganize your wallet, blow your nose, and put a new CD in the stereo. PULL FORWARD to do all these tasks so the next poor slob in line (me) can spend literally 45 seconds depositing a check.
image credit: http://www.darbyhudson.com