Difference between revisions of "Multiplication"
| Line 20: | Line 20: | ||
*[[Multiplication Property of Equality]] | *[[Multiplication Property of Equality]] | ||
*[[Math]] | *[[Math]] | ||
| + | |||
| + | [[Category:Mathematics]] | ||
Revision as of 13:31, March 11, 2007
Multiplication is a mathematical operation. Multiplication of positive integers is the same as repeated addition. You multiply two numbers together; that is, multiplication is always performed on two operands. The result is a third number Multiplication is repeated addition. For example:
- 3 times 2 = 2 added three times = 2 + 2 + 2 = 6.
This also works the other way:
- 2 times 3 = 3 added two times = 3 + 3 = 6.
2 x 3 = 3 x 2, regardless of the order of the operands. It is said that multiplication is commutative.
Multiplication is mentioned in the Bible when God tells Noah to go forth and multiply. (Joke! Really that is a different kind of multiplication.) However, Noah did have to use multiplication when he made the ark, because Genesis 6:15 says:
- And this is the fashion which thou shalt make it of: The length of the ark shall be three hundred cubits, the breadth of it fifty cubits, and the height of it thirty cubits.
So Noah knew the ark had to be a volume of 300 times 50 times 30 is 450000 cubics3, to fit two of all the animals in the world in it.
Multiplication is sometimes confusing because the symbol for multiplication is very similar to the letter x; but the letter x can also stand for a variable in algebra, as in "solve for x."
In printed material, slightly different symbols are used for the letter x and the multiplication symbol ×. Sometimes, in mathematics, a centered dot is used to stand for multiplication:
- 3 · 2
- a · b
- 6.022 ·1023
In algebra, quantities may simply be juxtaposed (written next to each other) without any symbols, to indicate multiplication. In this expression, 2ab means 2 times a times b.
- a2 + 2ab + b2