Just when I thought I was getting better at math...

[shadowkat]

This

Post by Power 95.3.

made me scratch my head.


7 + 7 divided by 7 +7 x7 -7.

The correct answer is apparently 50.

IF you do it this way: 7+7 =14 divided by 7 =2
2 +7 = 9, 9* 7 =63, 63-7 = 56.

If you do it by calculator = 56

If you do it by Excel = 50

Apparently it is supposed to be 7x7= 49 /7 = 1, then 1+7+7 -7 = 8.
Which still makes no sense. So, it must be = 7x7/7 =1, then 7+7+7 =21 +1
Still makes no sense. I remain puzzled.

This is why I hate math.

Comments

[shadowkat67.livejournal.com]

Here's why I got confused:

If I do the multiplication and division first:

7x7= 49 /7 = 1, then 1+7+7 -7 = 8.

Which is not 50.

So what you should have said is multiply, get a total, divide, get a total, then plug those totals into the formula thus:

7 (+1)+(49)-7

Makes so much more sense.

[flake-sake.livejournal.com]

but 7x7 and 7/7 are linked with a + so it is clear that 49/7 can't be in there, no?

[shadowkat67.livejournal.com]

Not unless I'm thinking of it in those terms. I wasn't. This gets into how differently people interpret and think about things.

So when people on FB said "do the multiplication and division" first then add and subtract from left to right, they made the assumption that I was thinking in the same terms they were. It was obvious to them - because that's how they were thinking.

But I read it as - oh you do the mulitiplication and division first, thus : 7x7/7, then you add and subtract from left to right.
I'm not thinking of a plus sign as a connector between the division sign. Also, once you tell me that the multiplication and division must be done first - you are changing the sequential order of the numerical sentence. So, I try to group it logically by how it was conveyed - which for me is, oh okay, multiply and divide this first, then add and subtract - that is after all what was said. What you didn't say: divide. Multiply. Plug in. Compute left to right. Which would have been clearer to someone who doesn't think of it the same way.


I do a lot of communicating for a living - where I have to explain things that are obvious to one group of people to a group who has never seen or doesn't know anything about it. The mistake is thinking what is obvious or logical to you is going to be for someone else. It never is.

[flake-sake.livejournal.com]

Yep, science can be a different language at points. Once you know the vocabulary it's clear as day and leaves very little room for interpretation. But in the beginning it just looks insane.

It's the same for me and programming languages. I always have a phase, where I'm going half mad,trying to get their logic.

[shadowkat67.livejournal.com]

Law is similar - it's a whole different language, takes a while to get it down. I'm constantly interpreting it for people. Same with engineering, railroad or industry specific languages, and well net-speak. Not helped by the fact that words, phrases, numbers, and abbreviations have different meaning depending on which industry, field, or business you are working in.

For example?

ETA?

On the internet it means - edited to add. In business it means - Estimated Time of Arrival.

Or RFP? In business it means Request for Proposal. For some people - Red Frigging Print.

I've realized that when you are communicating with someone outside your field of expertise - you need to find a way to explain it in terms that make sense to them. It's not as easy to do as it sounds. It's to a degree what I've done for a living - explaining to the lay-man, what a lawyer, IT, engineer, or specialist are trying to say.
And of course most of these people think - "well it's obvious, everyone should get it. Or they should learn it. I shouldn't have to explain myself." Which results in miscommunication, and unnecessary tension. I think part of the problem - is it has become so obvious and so routine (they do it every day that it second nature to them), that it doesn't make sense that someone else doesn't see it or get it.

I'm training a guy at work, bright guy, who is a Russian immigrant and speaks English as a second language and came from a different industry and business. I have to realize that what is obvious to me, won't be to him. So I told him up front - there are no stupid questions. And I constantly remind myself to be patient. Not to make assumptions. It's hard.

[shadowkat67.livejournal.com]

Eh, sorry for all the typos. I've been trying to do this without my reading glasses, mainly because I'm still in denial. LOL!