Japanese proverb about sushi

「サバを読む」(sabawo yomu)
Do you know the Japanese proverb?サバ(SABA) means a mackerel in English.
It shows “cheating in counting”.
in old days, a person counted a fish one by one and bought and sold it.
So buying and selling of the fish was easy to produce a mistake for an order when quantity of trade increased. and a number was not often correct
This is origin of the proverb.
The mackerel which is the material of the sushi appears in the familiar place of the people’s life ,like the proverb

皆さんはこの日本語のことわざについてご存知ですか?さばは英語では「a mackerel」と言います。