1 Arabic numerals were not invented by Arabs, but originated in ancient India, and were later mastered, improved and spread to the west by Arabs, who called them Arabic numerals.

2 "+"comes from Latin "et" (meaning "and"). /kloc-in the 6th century, the Italian scientist Nicolo Tartaglia used the initial letter of "più" (meaning "add") to indicate adding, and the grass was "μ" and finally became "+". The number "-"evolved from the Latin word "minus" (meaning "minus"), abbreviated as m, and then omitted the letter, it became "-".