I. Read the article. Guess the meaning of the highlighted words. Check with the teacher or your dictionary
II. Read the article again. Say what events the following years refer to:
1150 1550
1557 1672 1710
III. Tick (√) the things the article says
1. The earliest symbols for plus and minus that have come down to us are Egyptian.
2. The Hindus were likely to represent a negative quantity by a dash placed above the number in the 10th century.
3. The first symbols for plus and minus found in Egyptian writing looked like a pair of legs.
4. In Europe the word minus in connection with subtraction was used earlier than the word plus to indicate addition.
5. The bar above the letter was often used by most writers in the fifteenth century.
IV. Read the facts listed below. In pairs, discuss which one is the most surprising do you know that...
- The name for zero is not settled even yet. Older names and variations include naught, tziphra, sipos, tsiphron, rota, circulus, galgal, theca, null, and figura nihili.
- Thomas Harriot (1560-1621),an English mathematician,was the first to make use of these symbols: ">" for "is greater than" and "<" for "is less than".
- The
Anglo-American symbol for division is of 17th century origin, and has
long been used on the continent of Europe to indicate subtraction.
Like most elementary combinations of lines and points, the symbol is
old. It was used as early as the 10th century for the word est. When
written after the letter "i", it symbolized "id est."
When written after the word "it", it symbolized "interest."
I
f
written after the word "divisa", for "divisa est",
this might possibly have suggested its use as a symbol of division.
Towards the close of the 15th century the Lombard merchants used it
to indicate a half, along with similar expressions such as this one
o
n
the right.
- The symbol n! for "factorial n", now universally used in algebra, is due to Christian Kramp (1760-1826) of Strassburg, who used it in 1808.
- O
ur
familiar signs, in geometry, for similar and for congruent are d
ue
to Leibniz (1646-1715.)
- This symbol for pi was used by the early English mathematicians William Oughtred (1574 -1660), Isaac Barrow (1630-1677), and David Gregory (1661-1701) to designate the circumference (or periphery) of a circle. The first to use the symbol for the ratio of the circumference to the diameter was the English writer, William Jones, in a publication in 1706. The symbol was not generally used in this sense, however, until Euler (1707-1783) adopted it in 1737.
- In 1923, the National Committee on Mathematical Requirements, sponsored by the Mathematical Association of America, recommended this symbol (on the left) as standard usage for angle in the United States. Historically, Pierre Herigone, in a French work in 1634, was apparently the first person to use a symbol for angle. He used both the symbol above as well as this symbol on the right, which had already been used to mean "less than." The standard symbol survived, along with other variants, as follows.