Difference between revisions of "Multiplication"
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| − | + | In its most elementary form '''multiplication''' may be defined as repeated addition of whole numbers ([[integers]]). | |
| − | ''' | + | :For example, <big><math>2\times 3 </math></big> (spoken as "two times three") is the sum of 2 + 2 + 2. |
| + | In this example the numbers "2" and "3" are known as the ''factors'' and the result of a multiplication is knwon as the ''product''. | ||
| − | Multiplication is a [[commutative]] operation | + | Multiplication is a [[commutative]] operation in that A <big><math>\times</math></big> B = B <big><math>\times</math></big> A. |
| + | :For example <big><math>3\times 2 </math></big> (spoken as "three times two") is the sum of 3 + 3 = 6. | ||
==Symbol== | ==Symbol== | ||
Several conventions are used to indicate multiplication. | Several conventions are used to indicate multiplication. | ||
| − | *For simple numbers, the symbol used looks much like the letter "X", as in the examples above. | + | *For simple numbers, the symbol (<big><math>\times</math></big>) used looks much like the letter "X", as in the examples above. |
*Since the "X" looks like a letter, and letters are commonly used in algebra to indicate unknowns, or variables, the "dot" is frequently used: A • B = B • A. | *Since the "X" looks like a letter, and letters are commonly used in algebra to indicate unknowns, or variables, the "dot" is frequently used: A • B = B • A. | ||
| − | *Also, in | + | *Alternatively a period may be used to denote multiplication |
| + | *Also, in [[algebra]]ic use, quantities are simply juxtaposed to indicate that they are to be multiplied: | ||
| + | : Y = 3aX + 4bZ | ||
==See also== | ==See also== | ||
Revision as of 19:42, September 1, 2008
In its most elementary form multiplication may be defined as repeated addition of whole numbers (integers).
- For example, <math>2\times 3 </math> (spoken as "two times three") is the sum of 2 + 2 + 2.
In this example the numbers "2" and "3" are known as the factors and the result of a multiplication is knwon as the product.
Multiplication is a commutative operation in that A <math>\times</math> B = B <math>\times</math> A.
- For example <math>3\times 2 </math> (spoken as "three times two") is the sum of 3 + 3 = 6.
Symbol
Several conventions are used to indicate multiplication.
- For simple numbers, the symbol (<math>\times</math>) used looks much like the letter "X", as in the examples above.
- Since the "X" looks like a letter, and letters are commonly used in algebra to indicate unknowns, or variables, the "dot" is frequently used: A • B = B • A.
- Alternatively a period may be used to denote multiplication
- Also, in algebraic use, quantities are simply juxtaposed to indicate that they are to be multiplied:
- Y = 3aX + 4bZ