How to write opening and closing symbols in kindergarten mathematics

The invention and use of mathematical symbols are later than numbers, but their number exceeds numbers. There are more than 200 mathematical symbols commonly used in modern mathematics, and each symbol has an interesting experience.

Development course:

For example, there used to be several kinds of plus signs, and the "+"sign is commonly used in modern mathematics. "+"comes from Lavin "et" (meaning "harmony"). /kloc-in the 6th century, Italian scientist Nicolo Tartaglia used the first letter of Italian word "plu" (meaning "add") to indicate addition, and the grass was "μ", which finally became "+". The number "-"is derived from the Latin word "minus" (meaning "minus"). It was abbreviated to M at first, but later it was simplified to "-"because it was written quickly.