Quick accounting: 01 (Multiples of 5)

I first saw this happen as a 15-year-old in Singapore having a dim sum meal, which was a fairly new import at the time -- to my consciousness anyway.  

    For those interested, dim sum is a Cantonese cultural practice.  Its proper name is 飲茶 / yum cha [yǐn chá in Mandarin] / "drink tea", for the activity.  The original practice (started during the Qing era) was a social gathering of people (family, friends) over a few cups of tea, usually at the weekend or a festive day.  Because it's not good, health-wise, to have tea on an empty stomach, the tea drinkers would order "snacks" [點心 dim sum / diǎnxīn in Mandarin] in the form of dumplings and other small items of food that are not for a main meal.

    In time, this practice became popular for the eating rather than the tea drinking, and a new concept of dining out was born.  Now you know why Chinese restaurants stop serving dim sum at 5pm -- because it's not considered a proper / main meal.  No one eats those dumplings for dinner.  Not even for a proper meal, really, but acceptable in the day.

    The British equivalent would be eating peanuts, crisps and/or pork scratchings with the alcoholic drink in a pub, because it's not good to drink on an empty stomach -- or maybe it's boring to just drink.  Westerners might not have the same perspective on health issues as the Chinese. 

    At the restaurant I was taken to in Singapore as a teenager, the offerings came on trolleys that perambulated within the restaurant.  The dishes were the same price, which is how the system works so well.  Dishes with more expensive ingredients, e.g., prawn, would have fewer items.

    When you saw that the trolley that came round had what you wanted, you'd indicate your interest. The waiting staff would put it/them on your table, then, on the piece of paper left on your table, record the number of dishes you've taken in the form of a build up of strokes in the character 正 (zhèng / upright, but the reading and meaning are irrelevant here in this context).

    The 正 character is made up of five strokes.  There is a fixed order for writing characters, with the one for 正 being:

1st stroke:  top horizontal (full stroke), written left to right

2nd stroke:  middle vertical (full stroke), written top to bottom

3rd stroke:  middle horizontal (half stroke on the right of the middle vertical), written left to right

4th stroke:  left vertical (half stroke on the left of the middle vertical), written top to bottom

5th (and final) stroke:  bottom horizontal (full stroke), written left to right

    If your first lot is three dishes, the 正 character would be incomplete, with only three strokes written in.

    If your next lot is three dishes again, two of these three dishes would complete the first five-stroke 正 character, with the third dish being the first stroke of the next 正 character.

    The Western equivalent is the system of four vertical lines with the final line written as a horizontal line across.  This is most often seen in films on the wall of a prison cell with the captive person keeping track of how many days have passed.

    The problem with the Western version is that one might write five vertical lines (or three) and it might not be obvious, as they can/might be a bit close together.

    With the 正 character, if there's one stroke missing it'll show up immediately.  (One stroke too many will not happen unless the person is totally illiterate.)  Of course, the final toting up might not see the last 正 fully written out (with five strokes), as diners don't conveniently order/eat in multiples of five.

    So, when it comes to adding up, it'll be x number of fives, plus whatever number of strokes there are in the final incomplete 正, multiplied by unit price of dish.  Bob's your uncle.