Finger Multiplication for the 9s

Date: 06/10/98 at 10:29:16
From: Samantha
Subject: Math

I don't know my 6, 7, 8,and 9's times tables. Can you help?

Yours truly,
Samantha

Date: 06/12/98 at 23:05:52
From: Doctor Becky
Subject: Re: Math

Hi Samantha!

Memorizing stuff can be a big pain. Luckily though, there are ways to 
make memorization easier. When I was learning my times tables, my 
teacher taught me a special trick for learning the 9's. Here's how it 
works:

Hold your two hands together so that all of your ten fingers are out 
in front of you. Give your fingers numbers from 1 to 10 from left to 
right, so the pinky on your left hand is 1, and the ring finger is 2.  
Keep going like that. (Your left hand thumb is 5, your right hand 
thumb is 6 ... all the way up to your right hand pinky, which is 10.)

Now think of what number you want to multiply by 9. Let's choose 4 as 
an example. The number you are multiplying by 9 is 4, so fold down 
your fourth finger (The index finger on your left hand.)  Now look at 
your two hands. See how there are 3 fingers up, then 1 down, then 6 
more up? We read this as 4 times 9 is 36. 

Try it again, this time with 6. Fold down your 6th finger (Your right 
hand thumb.) See how there are 5 fingers up, then one down, then 4 
more up: 9 times 6 is 54. 

Do you see the pattern? You look at the number of fingers to the left 
side of the folded down finger to find out what number is in the 10s 
column of the answer, and you look to the right of the folded down 
finger to find the number in the ones column. 

That trick only works for the 9's. I wish I had tricks like that for 
the other ones too, but I don't. All I can say is keep trying. 

When I memorize stuff I like to use flash cards. Have you tried that?  
Sometimes they help a lot. Other times I like to write things down 
over and over again or say them out loud to myself over and over until 
I remember them. Remember, don't try to memorize too much at once.  
You will just get more confused and frustrated. Try memorizing just 
one or two things a day. Also, it's great that you are getting help 
from your family. 

Keep up the good work. Good luck!

-Doctor Becky,  The Math Forum
Check out our web site! http://mathforum.org/dr.math