My husband and I were talking about multiplication the other day and I let slip that I don't have my upper times tables memorized. 5 is about as far as I go.

"So how would you multiply 7*9?"

I answered that I'd do 4*9 and then add it to 3*9. Or I might use the ascending/descending pattern of the 9 times table and count down - 9*9=81, 9*8=72, so 9*7=63 He looked at me like I was crazy.

I probably could memorize the upper tables but I never bothered and this method doesn't seem like much extra trouble to me.

I'm wondering who out there has the tables memorized and who uses tricks or alternate methods?

## 10 comments:

I do what you do...

7*9 = 7 *10 - 7....

:)

5*8 = 5*6 + 5 +5......

:P

I am actually teaching my kids this way as well....

it works for me.... so i dont; see the harm....

Memorized, but I'm a math person and ex accounting manager. Hubby doesn't know them, hardly any at all. He doesn't care either. However he has nervous issues about going to a store for an item and not having enough money, can't tell while standing at a cash register if he's been overcharged, doesn't know when I bill doesn't make sense, stuff like that. I don't know if it's because math is just not his thing or because he was so poorly served by schools. So math literacy and logic is something I very much want the kids to have. For that reason I am postponing rote knowledge of facts for as long as possible, but I do want them memorized, after the logic is there.

DEb - I was looking at JUMP Math (jumpmath.org) and a sample fractions unit they have teaches something similar I think. Just a few of the times tables and then showing how you can double the results and such.

Lorraine - You're weird. I can't relate to you on this matter. :)

LOL. I can't imagine now knowing times tables. They're as simple to me as the ABCs.

Well. You made me feel better. I can up to my 7 times tables.. then I add.. just like you :-)

My firned once suggested that I may have something called "dyscalculia" a kind of dyslexia of numbers. I am always dropping numbers and transposing them. I CANNOT remeber a number if my life depended on it. Do you have trouble with phone numbers or other numbers you should know??

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I don't know if I have similar problems with numbers. I can remember phone numbers but it's gneerally with the use of some kind of trick...if it's 734-2930 (randoly typed) I'd remember the first three by thinking 10+4=14 and the last four by thinking of 29 and 30 in sequence. Sounds complicated now that I'm typing it but I bet you I won't forget that number now. :)

I use the hand method. Lets say you say 9*3 - you hold you hands up and on the left hand put down your 3rd finger (cause you multiply by 3)then you have 2 before the finger you let down and 7 after the finger you put down and the answer is 27.

I have to admit that if the answer is much over 50 I probably have to stop and think about it a bit. But thinking is the fun part, right?

I'm lost after 6. I do have 9's, but I've always remembered those in a weird way. It sounds more complicated when I explain it than it works in my head. It goes: 9x7, one less than 7 is 6, 7+3=10, 9x7=63. In school they taught us to add to 9, 6+3 is 9 so 63, but I always did it this way because 10's were easier to add to.

Most of them I know, but have to think about it a sec and say, "Is that right? Crap." I'm drilling, drilling, drilling my kids on multiplication because I don't want them to have the trouble I've had.

Well, I'm happy to know I'm not the only one out there. Frankly, I don't think it's a failing...It takes a bit of mental gymnastics to multiply our way and as Rolfe pointed out, that's a good thing! :)

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