A cool math trick

[sewchick]

This is something my Dad taught me years go. So please be patient it's been a long time since I have done this.

A young man went looking for a job. He happened upon a small store with a sign that said help wanted. He went in and the owner said if you can do this little test by the time I get back I will give you the job. The young man was not too smart. He failed in math. And what did he get? A math question. Here is what he was given:

1x9=
2x9=
3x9=
4x9=
5x9=
6x9=
7x9=
8x9=
9x9=

As the young man looked at the 9 table he decided to go down through them and mark off the ones he didn't know.

The I don't know part would not be written on the paper.

1x9=9 I know this one
2x9=1 I don't know
3x9=2 I don't know
4x9=3 I don't know
5x9=4 I don't know
6x9=5 I don't know
7x9=6 I don't know
8x9=7 I don't know
9x9=8 I don't know

After mulling it over for a minute he decided to go back through them just to make sure. He started at the bottom of the 9 table.

1x9=9 I know this one
2x9=18 I don't know
3x9=27 I don't know
4x9=36 I don't know
5x9=45 I don't know
6x9=54 I don't know
7x9=63 I don't know
8x9=72 I don't know
9x9=81 I don't know

The store owner came back and looked that the paper and said YOUR HIRED!!!

 

[TheOLDNewChick]

That's the only way I can remember my 9's in multiplication. I figured that out around the third grade. See, I suck at math...and I mean something terrible. I drilled my multiplication tables, but it never did stick.

Again, the only way I can remember my 9's is that the first digits go in order after "9", and the second digits go backwards starting at "9".

 

[chicken_boy_Kurt]

I learned something else to remember my 9 times tables but I don't remember ti really...

 

[sewchick]

Quote:
That joke has been around for a very long time. I learned it when I was a kid. 40 or so years ago.

 

[Zahboo]

9s are easy. lol. hold out all fingers. 9x2 hold down your second finger the finger on the left of you folded finger is the 10s column the ones to the right are the ones column. it even works for 9x10!

 

[Fancie]

yep I am not good at 7 or 8 in multiplication, but I pretty much figured the rest out. you figured I would have memorized the last teo by now...

 

[sewchick]

I have to laugh. Now days most of the young crowd cannot make change without a calculator. My dh is so funny. He purposely confuses the young clerks. 9 x's out of 10 they have problems figuring it out. It's ok he does not know liquid measurement without looking it up and I still grit my teeth when I have to do fractions.

 

[Zahboo]

My Algebra 2 teacher won't let us use calculators until we can do it by hand. VERY ANNOYING LOL

 

[Run-A-Muck Ranch]

Quote:
Never knew this one until my kids showed it to me...
I still get confused and what not, but I understand it a little bit at the same time....

Heck I took Cal. and Tri. In Highschool for math....

 

[Run-A-Muck Ranch]

Quote:
I have never in my life heard or seen this one before...
Sure wish I would of known it sooner....

Like I said in my other post....I took calculus and trigonometry as 2 of my math classes in highschool...I passed with A's, but I never ever knew this trick...
And calulators were not even allowed.