In Word, format-Chinese layout-circled characters can set up to two characters.

Besides counting, mathematics needs a set of mathematical symbols to express the relationship between number and number, number and shape. The invention and use of mathematical symbols are later than numbers, but they are much more numerous. There are more than 200 kinds in common use, and there are more than 20 kinds in junior high school math books.

The appearance of mathematical symbols

Counting symbols on wood, bones or stones have been used since prehistoric times. Stone age cultures, including ancient Indians, used counting symbols in gambling, private services and transactions.

From 8000 BC to 3500 BC, Sumerians invented the use of clay to retain digital information. Their practice is to string together small mud marks of various shapes like beads.

From about 3500 years ago, clay symbols were gradually replaced by digital symbols. These digital symbols are carved on the clay block with a round pen needle and then fired. About 3 100 years ago, digital symbols were separated from counted things and became abstract symbols.