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All entries for November 2010

## November 30, 2010

### Task 2.3 c

**TASK C: The history of zero**

The concept of zero seems obvious to us nowadays, but actually has a long and complex history, not coming into widespread use in Europe until the 17th century. Read the article A history of Zeroat the MacTutor website, and answer the following questions:

- Why is zero an important concept in mathematics?
- Why did zero take so long to become established within number systems?

Zero has become important within maths as a place marker and a “digit” in its own right. Within mathematical place systems it has become vital as a means of separating numbers and showing place value. Other systems had developed punctuation marks to show that there was a gap- ie 2”6 where we would write 206 but systems based on pictures/ symbols had no need for a zero- there just wasn’t a picture there. Rather than there being any misinterpretations the use of zero makes numbers explicitly clear as the 0 shows one space. a gap could be one zero, none or more.

Zero is also important as a means of separating positive and negative numbers- a neutral space so show that something was there but has now been taken away (or added) – a little like a debt being paid off. The zero records that there was a debt but that it has been cleared.

Mathematicians also perform numerous calculations with a zero- the concept of infinity arises when a number is divided by zero.

Zero was “invented” by different civilisations over time- Mayans, Babylonians and Greeks had some form of zero which was used and then died out. It wasn’t until the Indian mathematicians developed it that it eventually came into widespread use- even then it took hundreds of years to become established.

Some civilisations didn’t really see the need for a zero – as mentioned earlier – within systems using pictures and symbols the zero was depicted by a lack of symbol. The context in which the number was used appears to be more important than accurately the number. Indeed some mathematicians suggest that Christian teachers didn’t like the concept of zero and shied away from its development. They believe that it took Hindu mathematicians who believed in a void to develop the concept.

Much of the historical use of maths was in a very practical way and so that if you have 5 horses and sell 5 you don’t have any left and there is no need to record that fact. Historical mathematicians used maths to record passages of time or to map the movement of stars- again the use if zero is not relevant. Only when maths was started to be used in theoretical ways – what was called pure maths when I was at school- that the zero became relevant.