# 2.1 History of Numbers

Let’s start this chapter with some history. The numbers we use today, called Hindu-Arabic numbers, are a combination of just ten symbols or digits: 1, 2, 3, 4, 5, 6, 7, 8, 9, and 0. These digits were introduced in Europe during the thirteenth century by Leonardo Pisano (also known as Fibonacci [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] ), an Italian mathematician. Pisano was educated in North Africa, where he learned and later carried to Italy the now popular Hindu-Arabic numerals.

The Hindu numeral system is a pure place value (or base) system, which is why you need a zero, as we’ll see later.

[ Did you know that a symbol representing “nothing” has been found on tablets dating from 700 bce? It wasn’t until much later that the symbol we know as zero was adopted and used systematically. ] Mathematician Bertrand Russell called the invention of zero “the greatest achievement of the human mind.”

And not everybody needs numbers. It’s said that there’s a tribe in the Trobriand Islands in the South Pacific who only have three numbers: “one,” “two,” and “many.” Works for them …

One of the main reasons the number system developed and continues to develop is so that people can use numbers to solve a wide variety of important problems in trading, building, and navigating, although in this chapter, we will be concentrating on more everyday problems.

2.0.4 Working Through Unit 2

2.1.1 Written Numbers Compared