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## #1 This is Cool » Multiplying Large Numbers in your head » 2021-01-07 17:01:23

ericnumberking
Replies: 0

This is a quick way to multiply two-digit numbers by 11 in your head. Created by a banker believe it or not.

Let's say you are trying to multiply 72 x 11.

Which equals to 792

- Split 72 in to two digits (72 becomes 7 and 2).
- Then add these two digits together (7+2=9)
- Now place 9 in the middle of 7 and 2 and what do you get? 792

Pretty sweet eh?

Let's try that with another number . . . 56 x 11
which equals to

- 56. So 5 And 6
- 5 + 6 is 11 (Just carry the one to the first 5. So 5 becomes 6)
- Answer  is (Drumroll . . .) = 616

Try it out!

## #2 Coder's Corner » Crystal? » 2019-10-16 16:29:08

ericnumberking
Replies: 1

Anyone familiar with this 'Crystal' topic? Apparently it's on the rise (Big within the Ruby community). It's gaining quite of momentum for creating applications / generators as well.

## #3 Maths Teaching Resources » Are these any good? » 2018-02-08 09:26:34

ericnumberking
Replies: 2

So I've seen a few of these sites for Algebra like:

Math papa
Study Pug
Tutor

I would love to get some extra help right now but I'm not sure if these sites are trust worthy. I'm currently developing a robust employee payroll scheduling software so need to brush up on my coding and math skills.

Has anyone tried them? I don't mind paying for them with an excel invoice or something.

Also please PM if you are offering like Skype or online lessons. Just need to improve my Algebra and get my credits. As an hotel seo specialist, I'm a big fan of math.

I can pay you by a paypal invoice or some kind of excel template is fine as well. Overall though, I have a good feeling about learning online because when I took a few classes on teeth whitening, it was quite fun and informative. Heck I even learned about teeth chipping which was totally a surprise.

## #4 Re: Puzzles and Games » This Sudoku's unsolvable, correct? » 2018-02-08 09:16:48

MajikWaffle wrote:

Teacher gave that as a problem of the week, and from what I've done I figured it was unsolvable. Kind of messed up POW if it doesn't even work...

This is  tough one bud. I know someone that are always playing Sudoku but they are at work right now. When this person comes back, I'll get them to give it a shot.

## #5 Re: Computer Math » How a computer sees it. » 2018-02-06 09:15:34

bobbym wrote:

I may have been a bit hasty when I wrote that. I meant to say a lot better.

And the truth shall set you free . . . good one! It is come to my knowledge that orthodontist software used in practices use this too.