If you look at any mathematics book written before 1500's, it will be very hard to understand.The Hindu -Arabic numerals familiar to us may have been used. Every thing else was different. The signs and symbols that make up the rest of the language of mathematics as we study it today had not yet been invented.

The sign and sign for subtraction first appeared in 1489 in a German arithmetic handbook. They may have been borrowed from signs used by merchants to mark certain packages . A +was marked on packages with too much of whatever the package contained, while a - meant too little.

The sign for multiplication was invented by an Englishman William Oughtredin 1631.

The sign for division was invented earlier by a German mathematician Johann Heinrich Rahn.

The = for "equals" was invented by the English mathematician Robert Recorde in 1557.