Negative Numbers

Do you know what is a Negative Numbers?

- is a real number that is less than zero.

- are usually written with a minus sign (-) in front.

Examples:-1, -2, -3, -4, -5 …

Negative Numbers

History of Negative Numbers

• Negative numbers appear for the first time in history in the Nine Chapters on the Mathematical Art

• In the Nine Chapters red rods used to denotes negative numbers and black rods for positive numbers.

• In Hellenistic Egypt, the Greek mathematician Diophantus in the third century A.D. referred to an equation that was equivalent to 4x + 20 = 0 (which has a negative solution) in Arithmetica, saying that the equation was absurd.

• During the 7th century AD, negative numbers were used in India to represent debts.

• The Indian mathematician Brahmagupta, discussed the use of negative numbers to produce the general form quadratic formula that remains in use today. He also found negative solutions of quadratic equations and gave rules regarding operations involving negative numbers and zero.

Examples:A debt minus zero is a debt.A fortune subtracted from zero is a

debt.

• He called positive numbers "fortunes," zero "a cipher," and negative numbers "debts."

• During the 8th century A.D, the Islamic world learned about negative numbers from Arabic translations of Brahmagupta's works.

• The 10th century Islamic Mathematicians were using negative numbers for debts. The earliest known Islamic text that uses negative numbers is A Book on What Is Necessary from the Science of Arithmetic for Scribes and Businessmen by Abū al-Wafā' al-Būzjānī

• In the 12th century A.D. in India, Bhāskara II also gave negative roots for quadratic equations but rejected them because they were inappropriate in the context of the problem.

• In the 15th century, Nicolas Chuquet, a Frenchman, used negative numbers as exponents and referred to them as “absurd numbers.”

• In the 18th century it was common practice to ignore any negative results derived from equations, on the assumption that they were meaningless.

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