# Why Don’t They Teach Our Kids “Proof by Nine” As A Part Of Math?

by Anura Guruge

“Proof by Nine” (I have always called it (possibly incorrectly) “Proof of Nine”) is a clever and totally foolproof way to check your multiplication — without having to rely on a calculator or an electronic device. I was taught it, in Ceylon, at school, probably when I was around 6 or 7, as an integral part of learning to do multiplication. We are talking the early 1960s. We did NOT, especially in Ceylon, have calculators or for that matter even slide rules. So “Proof of Nine” was the ONLY way we had — and even our teachers — of checking the correctness of multiplication.

The 3rd image below (albeit purely scanned) in its first paragraph spells out EVERYTHING as it pertained to I. I would do “Proof of Nine”, by rote, as soon as I did a multiplication by hand. I still do it TODAY, for the fun of it. I have tried to teach the kids but they don’t fully grasp it.

The two articles I show here try to explain it very well. I did this diagram to show you the basic mechanics AND I KNOW that most of you are going to say that it is totally confusing.

Shame that they don’t teach it in school. Because all of us would know how to do it.

PLEASE look it up. It is very neat and awfully handy if you don’t have any other means to check a multiplication.

My diagram. So I want to check whether 7826 x 43 = 336518.

I start by drawing the slanted ‘X’. The I come up with the two vertical numbers, in this case 5 & 7. I do that by repeatedly adding the digits until I have but one digit. I ALWAYS throw out any 9 I encounter — and even digits that together add up to nine.

I multiply 5 x 7. That is 35. Add the digits. 8.

I add up the digits in 336518. I notice two obvious pairings that come to 9. 3+6 & 1+8. I throw those out. Actually it will still work IF I didn’t throw them out! All comes out in the wash. Well it adds up to 8.

The same ‘8’ I got when I multiplied 5×7 and got 35. The two ‘8’s match. The multiplication was RIGHT.

First article. Click to ENLARGE and read here. Use link below to access original.

Second article. Click to ENLARGE and read here. Use link below to access original.

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by Anura Guruge

# They Finally Put Correct Mailing Address On Paper Application For Obamacare (ACA) Health Exchange Coverage,

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### The new corrected form.

Click to ENLARGE. Get form from ‘healthcare.gov’.

### The original ‘XYZ Drive’ …

Note that this is THE ADDRESS I gave you, correctly, 9 days ago.

# I Apply For The Third Time For Obamacare (ACA) Health Exchange Coverage — This Time By Mail.

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>> Mailing address for paper application
>>Oct. 16, 2013.
>> Application says mail to ‘1005 XYZ Drive’ …
>> Oct. 9, 2013.
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### I have yet to be able to apply online using the poxed Website, though I have an account set up!

This is what I have done in terms of application so far:

October 2, 2013: After 16 hours of trying I managed to logon. But Website would not handle my dependents. Made application #1 on the phone via the Call Center.

October 8, 2013: Told the application I made Oct. 2 lost! Re-apply, i.e., application #2, by phone again, using Call Center.

October 14, 2013: I apply, application #3, by mail using paper forms and the correct address (because I am too smart to get fooled by Obama and his Canadian scam-artist cronies).

Still nothing.

# Paper Application Mailing Address For Obamacare (ACA) Health Exchange Coverage.

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>> Application says mail to ‘1005 XYZ Drive’ …
>> Oct. 9, 2013.
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### DO NOT MAIL to ‘1005 XYZ Drive’ as it says on application!

That was an Obama joke.

I dread to think of all the people who will mail it to this BOGUS address.

## The correct mailing address is:

Click to ENLARGE.