Multiplication Tables

I read a book once on mental arithmetic; it suggesting memorizing the times tables up to 20. After that, there are many tricks to break things down and do even complicated problems without pen and paper. I never did sit down and do it, though.

7 * 8 was the only one I could never remember. Then someone showed me:

56 = 7 * 8

Get it?

Mastery is not perfection but a journey, and the true master must be willing to try and fail and try again

I focused on the concept a bit too much in my teaching last year, I think. We did so many multiplication riddles, illustrations, etc. that my kids didn’t study/memorize facts. So, when I’d give them a timed test (3 minutes for 40 problems), many of them didn’t finish because they were sitting and adding 7 nine times to find 7x9, and the like. They got the right answer, and they all understood multiplication concepts, but when it came to the tests…well, they need to finish them to pass them.

“Me fail English? That’s unpossible!”

“English? Who needs that? I’m never going to England.”

My dad taught me this when I was a kid. I still think it’s just about the coolest thing I ever learned. Here’s how you can do your 9’s tables on your fingers: Hold your hands in front of you, palms facing your face, fingers spread. For this demo, bend your middle finger of your left hand down. now, counting from left to right, this is your third finger, thus, we are solving for 3 x 9. Each digit to the left of the bent middle finger represents 10. Each finger to the right of the bent finger represents 1. Add them up, and you’ll get 9 x 3 = 27. This works for any finger you choose. I’m not sure I explained it very well, so let me know if you have any questions.

“I think it would be a great idea” Mohandas Ghandi’s answer when asked what he thought of Western civilization

Sometimes I still have to find ones I remember and then add to reach the ones I don’t. 12’s? You gotta be joking.

If you lived in an area where you had to buy a Pee-Chee brand folder, it came with a 12 X 12 multiplaction table.

When I got bored in college, I would draw up multiplication tables. In one particularly dull class, I got up to a 25 X 25 table.

From now on I know that 323 is not a prime number.

I think Porpentine was on the right track. So many things come in dozens (inches, eggs, intelligent people) that it makes a certain amount of sense to memorize the multiplication tables for them. Granted, you can figure it out with 10s and 2s, but it’s quicker if you have it memorized.

Carpe hoc!

Quadell: OH YEAH!
That 3. It’s a magic number…

I’m just a Bill, Yes I’m only a Bill.
Your Pal,

In case no one knows their multiplication tables…


[Note: This message has been edited by Nickrz]

But an “A” for effort Louie.

I had as much trouble w/ memorizing multi tables as anyone, but I’m glad I had to. How’re you going to do squares later if you haven’t memorized what 2x2 5x5 etc are – without counting?

I had some mega-trouble with my 4s though.
Mid 80’s NYC public schools. We were supposed to go up to 12s. In order “pass up” to the next level, you had to stand in front of teacher (could be private if you were shy) and answer each verbally. No more than 5 secs for each question, and not in order.

Boy she was tough (but nice too). She let me read as much as I wanted as long as my other work was done. (my definition of good teacher!)

Being a teacher, who loves to teach math, I definitely have opinions on this subject. The new way of thinking on memorization of times tables is “don’t stress memorization, just make sure they understand the process”.
Memorization is not scene as authentic learning and one can memorize their times tables and still not know how to “think”.
But I disagree. That view may work on states and capitals–which are not necessary knowledge. But students who don’t memorize their times tables probably won’t get very far in math. I’m an elementary teacher and I’ve had occasion to talk to high school math teachers and every one of them has said that memorization of times tables is an absolute necessity.
<sigh> I know someone is going to say but I don’t want to get far in mathematics. But I can’t think of one career where math is not used even a little.
I also have a view that learning is a really cool thing and learning something challenging like your 11’s and 12’s has it’s own reward—that feeling of accomplishment
but I guess that comes from being a teacher.
One more thing–if you’ve learned your times tables to 11-12–for example 2x0 all the way to 2x12–you don’t really have much to learn when you get to 11’s and 12’s you already know most of them.

“Any major dude with half a heart surely will tell you, my friend–
Any minor world that breaks apart falls together again…”
-Steely Dan

Do you guys know there’s an album out called “Schoolhouse Rock Rocks!”
with various rock and rap artists doing covers of the old
Schoolhouse Rock tunes? Blind Melon does a great, trippy version
of “Three is a magic number” - probably the best song on the
record. The Lemonheads, “My Hero, Zero” is pretty good, too.
Better than Ezra’s version of “Conjunction Junction” is OK,
but really can’t hold a candle to the original - I don’t
know why they even bothered trying.

Thank you Nick, oh thank you, thank you!

Learned the concept of multiplication in 1973 (2nd grade. Was not forced to memorize anything (New Math in elementary school–lots of associative properties and set theory and base twelve or six or whatever) until 7th grade and algebra,oops, junior high, conservative teacher, like the old days, memorize those times tables up to twelve. This was probably 1979 and maybe just about the last gasp of teachers who made students memorize things. By the way, no teacher ever made me memorize the state capitals, though for some reason I know them.

I have “Schoolhouse Rock Rocks”! It’s very good - in some parts. The rap version of Mr. Morton is great.

I’m gonna have to agree with Gail about memorizing. I don’t like to memorize stuff, because it’s boring. (In Calc, rather than memorizing the quadratic formula, I just derived it on the test.) But still, it helps. This is even true with literature. After I memorize a couple poems, boring as it is, I find I appreciate them better. Something will come up in my life, and it’ll trigger a line, and I “connect” with it.

I just wish memorization wasn’t so dern boring!

Your Quadell

30 minutes of work down the drain. sigh Sorry about ruining the thread like that. And thanks, Nickrz, for deleting it.

Feeling ashamed :o,

Louie - there’s a thread over in the “About this message board” forum for testing silly graphics before you post them here. :wink:

When I learned multiplication (early 90’s) I only learned up to 10’s. Of course, my schools have always been lacking in strong math. I didn’t even learn how to multiply 3 digit numbers by 3 digit numbers on paper until my junior year! (Well I figured it out eventually but it was only a guess…I didn’t actually see it done until a looong night at Subway) They never taught us theory. I can figure things out if I go through the theory thing now, but memorizing the problems was pointless. They’ve long been forgotten now that calculators are available. I’m fortunate because I pick up on math concepts easily, so I can work it out without the memorization. But just spring a hard one up like 5*8 and I’m toast. (Someone said they had troubles with 6s and 8s…me too) If they are going to make calculators so readily available at such young ages, they should make sure to teach theory. People forget and become lazy, and then when they’re caught without a calculator they’re really in a jam! So either do away with calculators or start with theory because memorization plus calculators is as good as not learning at all. I’m not sure this post made any sense at all…it’s late. Sorry…

“Where it is a duty to worship the sun it is pretty sure to be a crime to examine the laws of heat.”
~John Morley

Since we’re on multiplication, here’s a fun little piece for all you math fanatics.

What is the smallest number that can be expressed as the sum of two different sets of cubes? (All the cubed numbers must be positive integers.)

Cave Diem! Carpe Canem!