Jump to content

Simple maths questions people argue about


Danny00135

Recommended Posts

I'm just a bracket nazi, clearly :lol:

Fight for your right, for brackets!

In all seriousness though, I've never heard of either of these things and I am probably the worst person on this forum at maths (math, whatever). I can do VB programming and fairly standard formula in Excel, but give me a question like the above and I would get it wrong like the 92% would....

  • Like 1
Link to comment
Share on other sites

7+7/7+7x7-7

= 7+(7/7)+(7*7)-7

=7+1+49-7

=50

Although, Bodmas, pidmas or whatever you use is fundamentally wrong.

For example 4 x 2 ÷ 4 - 2 + 10 = ?

This actually equals 10. Not -10.

Edited by JT!
Link to comment
Share on other sites

Bastardise the English language. Just not in this instance since here you just use different words to indicate the first two steps.

Haha, so true.

Exactly,

Plus you lot across the pond say math, which refers to literally nothing. Maths is actually an acronym and that's why us clever lot say it ;)

I'm going to need to start saying that instead of "math". See if anyone notices.

Link to comment
Share on other sites

I can't even remember having to work out a sum written in such a strange way either. Why not just use brackets?

Because you studied math before facebook and trolls were invented. I know the question was rhetorical but I chose to ignore that.

  • Like 1
Link to comment
Share on other sites

Where are your brackets?

Do you mean (4 x 2) ÷ 4 - 2 + 10

or 4 x (2 ÷ 4) - 2 + 10

There really isn't any need to put brackets in this one seeings as it's relatively simple.

If you did want to put brackets in it would look like this I believe:

(4x2/4) - 2 + 10

Although, Bodmas, pidmas or whatever you use is fundamentally wrong.

For example 4 x 2 ÷ 4 - 2 + 10 = ?

This actually equals -10. Not 10.

No dude, the answer is 10. Not sure how you managed to get -10 at all!

With bidmas it's 10 and without bidmas it still is 10.

A scientific calculator that has Bidmas programmed into it even says it is 10 :/

Link to comment
Share on other sites

Where are your brackets?

Do you mean (4 x 2) ÷ 4 - 2 + 10

or 4 x (2 ÷ 4) - 2 + 10

If I included brackets it would be a little pointless...

There really isn't any need to put brackets in this one seeings as it's relatively simple.

If you did want to put brackets in it would look like this I believe:

(4x2/4) - 2 + 10

No dude, the answer is 10. Not sure how you managed to get -10 at all!

With bidmas it's 10 and without bidmas it still is 10.

A scientific calculator that has Bidmas programmed into it even says it is 10 :/

I got them the wrong way round, edited.

Using podmas or bidmas or whatever will get you -10 because you'd be taking away 12 at the end instead of subtracting 2 then adding on 10.

Edited by JT!
Link to comment
Share on other sites

Do the division first

so

4 x (2 ÷ 4) - 2 + 10

Then the multiplication

(4*(2/4))-2+10

Then the Addition

(4*(2/4))-(2+10)

So then you have 2-(2+10) which equals -10.

That's what you get when you use BIDMAS, but it gives you the wrong answer.

Edited by JT!
Link to comment
Share on other sites

Do the division first

so

4 x (2 ÷ 4) - 2 + 10

Then the multiplication

(4*(2/4))-2+10

Then the Addition

(4*(2/4))-(2+10)

So then you have 2-(2+10) which equals -10.

That's what you get when you use BIDMAS, but it gives you the wrong answer.

It's still ten.

You did everything ok until the end when you put (2+10) into brackets.

Here's how I did it...

4 x (2/4) - 2 + 10,

4 x (0.5) + 10 - 2 (swapped these the other way around to deal with bidmas, doesn't particularly matter anyway as 4 x 0.5 = 2 - 2 = 0 + 10 = 10)

4 x (0.5) = 2 + 10 = 12 - 2 = 10.

I'm not totally sure why you're not supposed to bracket the last bit but I think it's because you have to leave the addiction and subtraction separate. I think if the original equation was:

4 x 2/4 - -2 + 10 then you could bracket the end bit as it requires work beforehand. Either way dude, just check on a scientific calculator if you're not convinced

Link to comment
Share on other sites

You add together the 2 and the 10 because that's what Bidmas tells you to do (to do the addition before the subtraction)

But you're totally missing my point, I know the answer is 10. What I'm demonstrating is that Bidmas is wrong and if you follow it you'll get a wrong answer. You're telling me I'm doing it wrong, when I'm purposefully doing it wrong. :lol:

Link to comment
Share on other sites

Yeah ok but you're doing it wrong wrong then ;)

Because bidmas doesn't say group the two sums together.

You can't parenthesis -2 + 10 at the end of a sum unless it's - -2 + 10.

Because the addition first would be +10 then - 2

Not - (2+10)

As far as I'm aware, you only parenthesis something that requires work beforehand.

I can see your point though, and I'm sorry I can't justify properly as to why it shouldn't be -10, I just know that you don't parenthesis the last part, regardless of bidmas.

I'll ask my mate who did a maths degree and see if he can give me a proper reason :D

Link to comment
Share on other sites

Yeah ok but you're doing it wrong wrong then ;)

Because bidmas doesn't say group the two sums together.

You can't parenthesis -2 + 10 at the end of a sum unless it's - -2 + 10.

Because the addition first would be +10 then - 2

Not - (2+10)

As far as I'm aware, you only parenthesis something that requires work beforehand.

I can see your point though, and I'm sorry I can't justify properly as to why it shouldn't be -10, I just know that you don't parenthesis the last part, regardless of bidmas.

I'll ask my mate who did a maths degree and see if he can give me a proper reason :D

Well once you've done all the multiplication and division, you're left with 2 - 2 + 10. Bodmas states that you do the addition first, which when you do you end up with 2 - 12. I'm only adding in the brackets to make it clearer.

I really don't get where the problem is here and I don't really get what you're saying.

Link to comment
Share on other sites

Yeah, but you are adding the 10 to the second 2 (-2) rather than the first 2 (2)

The operator ( * / + - ) belongs to the number directly after it, unless there are brackets after the operator.

So the -2 doesn't get involved until the very end.

Edit: This is very hard to explain over the internet and I am now getting confused...

Edited by AndrewEH1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...