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Arithmetic
Arithmetic
UK pre-decimal currency 4 farthings (f) = 1 penny 12 pennies (d) = 1 shilling 20 shillings (s) = 1 pound (£)
Arithmetic (from the Greek arithmos, "number") is a branch of mathematics that consists of the study of numbers, especially the properties of the traditional operations between them—addition, subtraction, multiplication and division. Arithmetic is an elementary part of number theory, and number theory is considered to be one of the top-level divisions of modern mathematics, along with algebra, geometry, and analysis. The terms arithmetic and higher arithmetic were used until the beginning of the 20th century as synonyms for number theory and are sometimes still used to refer to a wider part of number theory.
The prehistory of arithmetic is limited to a small number of artifacts which may indicate the conception of addition and subtraction, the best-known being the Ishango bone from central Africa, dating from somewhere between 20,000 and 18,000 BC, although its interpretation is disputed.
The earliest written records indicate the Egyptians and Babylonians used all the elementary arithmetic operations as early as 2000 BC. These artifacts do not always reveal the specific process used for solving problems, but the characteristics of the particular numeral system strongly influence the complexity of the methods. The hieroglyphic system for Egyptian numerals, like the later Roman numerals, descended from tally marks used for counting. In both cases, this origin resulted in values that used a decimal base but did not include positional notation. Complex calculations with Roman numerals required the assistance of a counting board or the Roman abacus to obtain the results.
4 farthings (f) = 1 penny 12 pennies (d) = 1 shilling 20 shillings (s) = 1 pound (£)
- If we have two sticks of lengths 2 and 5, then if we place the sticks one after the other, the length of the stick thus formed is 2 + 5 = 7.
- Reduction where a compound quantity is reduced to a single quantity, for example conversion of a distance expressed in yards, feet and inches to one expressed in inches.
- Expansion, the inverse function to reduction, is the conversion of a quantity that is expressed as a single unit of measure to a compound unit, such as expanding 24 oz to 1 lb, 8 oz.
- Normalization is the conversion of a set of compound units to a standard form – for example rewriting "1 ft 13 in" as "2 ft 1 in".
- Reduction–expansion method where all the compound unit variables are reduced to single unit variables, the calculation performed and the result expanded back to compound units. This approach is suited for automated calculations. A typical example is the handling of time by Microsoft Excel where all time intervals are processed internally as days and decimal fractions of a day.
- On-going normalization method in which each unit is treated separately and the problem is continuously normalized as the solution develops. This approach, which is widely described in classical texts, is best suited for manual calculations. An example of the ongoing normalization method as applied to addition is shown below.
- Addition of natural numbers
- Additive inverse
- Arithmetic coding
- Arithmetic mean
- Arithmetic progression
- Arithmetic properties
- Associativity
- Commutativity
- Distributivity
- Elementary arithmetic
- Finite field arithmetic
- Integer
- List of important publications in mathematics
- Mental calculation
- Number line
- MathWorld article about arithmetic
- (historical)
- The Great Calculation According to the Indians, of Maximus Planudes – an early Western work on arithmetic at Convergence
- Weyde, P. H. Vander (1879). "". The American Cyclopædia.
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Arithmetic