Talk:Multiplication

Removing Bible material whose relevance to multiplication is slim

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.

Since the first sentence is acknowledged to be a joke and not to refer to the arithmetic operation, it shouldn't be there.

The Ark example isn't very good, for two reasons. First, in the Bible, the product of the three numbers is not mentioned, so this is not an example of a use of multiplication in the Bible. (It would be very relevant in an article about the three dimensions of ordinary space).

Second, the computation as presented is almost certainly wrong, since the Ark was surely shaped shaped like a boat, not like a rectangular box, and therefore its volume would not have been 450,000 cubits³ but some subtantially smaller number, which cannot be calculated exactly from the given data. Dpbsmith 20:02, 22 March 2007 (EDT)

Multiplication table

This article should have the multiplication table ("times table"). I suppose that the generic child using Conservapedia already knows it, but having it for review purposes can't harm. In addition (pun not intended!), the table makes it easier to understand the whole concept of multiplication. Unfortunately, I'm completely wiki-ignorant, and don't know how to insert tables in articles. SilvioB 20:47, 30 August 2008 (EDT)

I think that's a very good idea... maybe I'll try to put something together. Human 17:28, 31 August 2008 (EDT)

Retreading previous material?

Didn't this article used to be longer? I was just putting in some stuff about the symbols used, and it seemed a bit deja vu. Was there a reason for deleting some of this article, and did I miss it? Didn't mean to re-add that which was decided was inappropriate... Human 18:15, 31 August 2008 (EDT)

Illustrations and examples

How about a diagram? I've taught multiplication to several children of one-digit age by showing them rows of objects. Like, 2 rows of 6 eggs is 12 (a dozen eggs) or three groups of two coins make 6 coins. Counting by twos is a cheap way to get started on multiplying (and by the way learning your two times table); see times table.

Don't be in a hurry to get all formal and grad schoolish. We need to give our readers practical knowledge. --Ed Poor ^Talk 21:36, 1 September 2008 (EDT)

Can you find and upload a picture of a carton of eggs for us to use? That would be cool. Human 16:47, 3 September 2008 (EDT)

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 &#149; B = B &#149; 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

Please rewrite the above content, which I just now removed from the article. (Do you know how to use article history? --Ed Poor ^Talk 08:16, 3 September 2008 (EDT))

I don't really see anything wrong with that content. What is confusing about it? Philip J. Rayment 10:04, 3 September 2008 (EDT)

In the UK when I was at school, a long time ago before the liberals ruined education with "modern math", it used to be the convention that X was the symbol for multiplication and x was the symbol for an unknown quantity.Malakker 10:08, 3 September 2008 (EDT) (sorry, hit the wrong button first time.)Malakker 10:08, 3 September 2008 (EDT)

An asterisk * is often sometimes used for multiplication (and / for division), especially on computer systems such as Microsoft Excel, although I have also seen it in printed documents as well. I believe (although I may be wrong) that this originates from its use in early computer programming languages such as BASIC. Sideways 10:39, 3 September 2008 (EDT)

Yes, that should be added to the list. I actually used it in place of the dot when I was writing the above while I went and searched for the code for the "dot product" symbol. And, yes, the 'sterisk goes back at least to BASIC. I think it's mostly because the dot isn't in the basic ASCII character set (also, it's not on your keyboard...). By the way, who added the incorrect "parentheses" example at the end of the article? Human 16:46, 3 September 2008 (EDT)

If someone can explain how multiplication is used in algebra, then a tiny note about * or "dot" may be in order. But not before. --Ed Poor ^Talk 20:04, 3 September 2008 (EDT)

I thought the "target" age group was "college bound high school age students"? Human 20:39, 3 September 2008 (EDT)

You thought right. Now stop blathering and do some writing. I want that on my desk in the morning, Jimmy Olsen, or by Great Caesar's Ghost I'll know the reason why! --Ed Poor ^Talk 20:43, 3 September 2008 (EDT)