remember FOIL?
A lot of adults don’t, then proceed to argue about order of operations, having forgotten that Brackets have to be all expanded out before doing anything else at all.
We don’t learn that math because it’s practical for adult life
Yes we do. I use Maths every day, quite separate to the fact I teach it.
No, I am saying you are wrong
And textbooks, calculators, accountants, and @sxan@midwest.social, who also explicitly pointed out that what you did was 10-(1+1). I see you didn’t read the textbook either then.
No one else
Nope, also all the other parties listed above, who all agree with me
The saddest, and funniest, part is that you are so egotistical that you don’t see why you are wrong
That would be you again, after it has been explained to you many times, by me, other commentators, and Maths textbooks.
Maybe you will get it one day, but I won’t be there for it
Again that applies to you only, the only one here who thinks 10-1+1=8 when doing addition first, even though 11-1=10.
Self reflection is good.
How do you know when you haven’t tried it yet? If you had, you would realise you also owe @cabron_offsets@lemmy.world an apology too
I know it is wrong, which is why I am telling you what my mistake was originally
But failing to understand what your actual mistake was, coming up with -1+1=-2, and not -1+1=-0
The fact that you still don’t get it demonstrates your complete lack of understanding
That would be you, the one who thinks order matters, and that -1+1=-2, not -0.
Order does matter
Nope!
+10-1+1=10
+10+1-1=10
-1+10+1=10
+1+10-1=10
+1-1+10=10
-1+1+10=10
Put those all into a calculator, and/or ask an accountant about it.
that order is left to right.
And yet, going RIGHT TO LEFT +1-1+10=0+10=10, same answer… though I have no doubt you think it’s +1-1+10=+1-11=-10
The original equation is written correctly
and 10-(1+1) isn’t, hence your continued wrong answer
My mistake was doing the addition before the subtraction when the equation reads 10 - 1 + 1
No, your mistake was doing 10-(1+1) where the question reads 10-1+1, and not +10+1-1 <== this is addition first, you add all the positive numbers together first, then do the negative numbers This is literally the textbook way to do it
According to you 6a²b-11a²b+5a²b-7a²b+2a²b=6a²b-16a²b-9a²b=-19a²b, and yet the textbook quite clearly states it’s -5a²b, which is because it’s 6a²b+5a²b+2a²b-11a²b-7a²b=13a²b-18a²b, and NOT 6a²b-(11a²b+5a²b)-(7a²b+2a²b)
10-(1+1)=10-1-1 which is what you did, which is not 10-1+1. You “added” 1 to -1, and got -2 instead of 0
How are you still not getting this?
It’s not me who’s not getting it.
No it wasn’t.
Yes it was. Read the textbooks.
The original equation is written correctly but the logic is incorrect
No your logic is incorrect. You’re incorrectly adding brackets to it.
in order to make it work the way I declared you have to do the equation x - y + z doing the y + z first
By putting it in brackets which is not how addition is done first. Doing addition first for x - y + z is x + z - y, not x - (y + z)
which was the mistake doing addition then subtraction
No, the mistake was you put the addition in brackets, -(1+1)=-2, not -1+1=+1-1=0. As per the textbook, the sum of any 2 numbers can only have 1 value. That 1 value for -1 and +1 is 0. -1+1=0, +1-1=0, not -1+1=-2
doing addition then subtraction instead of addition and subtraction in order from left to right
The rules are you either do addition then subtraction, OR you do left to right. There is no such thing as addition then subtraction left to right.
Addition then subtraction 10+1-1=11-1=10
Left to right 10-1+1=9+1=10
What you did 10-(1+1)=10-2=8
I see you are still being a bad teacher
says bad student, who didn’t try what the teacher said to try
who refuses to listen
that would be you again. You didn’t try it on a calculator, you didn’t ask an accountant. You didn’t even read and understand my examples. Read the textbook - it’s not just me telling you this.
I am not continuing with you
Because you’re unwilling to admit you’re wrong and refuse to try what the teacher and textbook have told you to do, and also refuse to ask an accountant about it
The fact that you still don’t get it demonstrates bad faith
Nope, that’s you again. You’re even arguing with literal textbook examples.
willful ignorance, and an unwarranted superiority complex
Also you, thinking you’re above Maths teachers, calculators, accountants, and Maths textbooks. According to you all of us are wrong, and only you are right. Get a grip
10-1+1=10 only if you don’t the addition first 1 + 1 = 2 - 10 = 8
Nope, yet again you just did 10-(1+1), which is wrong for 10+1-1. It gives 10 in any order. 10+1-1=11-1=10 <== did addition first, got 10. Accountants would have a nightmare if order mattered. “Did we receive this payment first, or this invoice? The order matters! ARGH!”
which was my mistake, which I already stated.
No, your mistake was adding brackets, 10-(1+1) ISN’T how to do addition first. 10+1-1 is. Ask an accountant! 😂 As you discovered 10-(1+1)=10-1-1, which isn’t 10+1-1, nor 10-1+1. 10-1-1=8, which is what you did - 10-1-1=10-(1+1) - 10-1+1=10, 10+1-1=10.
I see you still didn’t try it on a calculator yet then
Enjoy the egg on your face bud
None on my face. My students do very well in their tests. How about you? BTW try it on a calculator and guess what answer you’ll get. hint: it’ll be the same answer regardless of which order you do it 😂
To save you some trouble, here’s the results from my calculator…
10+1-1=10
10-1+1=10
-1+10+1=10
+1+10-1=10
-1+1+10=10
1-1+10=10
I feel bad for your students if you cannot see why you are wrong here
My students know I’m right. Everyone’s students know that’s right. It’s only adults who’ve forgotten the rules who get this wrong.
I am not going to argue with you about it
Nor should you. I’m a Maths teacher.
This was resolved almost a month ago
And yet you still don’t understand what’s wrong with what you said.
Read the original equation again, plug some numbers into it, and try again.
That’s what you need to do. You’re the one coming up with wrong answers when you change the order. Changing the order doesn’t change the answer.
If you still don’t get it I cannot help you
It’s not me who doesn’t get it. I teach it.
The brackets are used to make the equation look cleaner
No, they’re used to show deviations from the usual order of operations. If I want 2+3x4 to equal 20, then I have to write (2+3)x4.
10 - 1 + 1 = 8 doing the addition first
No it isn’t. 10+1-1=11-1=10 is doing the addition first. Note same answer. You in fact did 10-(1+1) - you added brackets which changed the answer, thus a wrong answer
10 - 1 - 1 = 8 regardless of order because it is all subtraction
Not all of it. You’re forgetting the 10 is really +10. -10-1-1 would be all subtraction. +10-1-1 is addition and subtraction.
it is not the same regardless of order
Yes it is! 😂 It is always the same regardless of order, as I have just shown you, again.
10-1+1=9+1=10
10+1-1=11-1=10
-1+1+10=0+10=10
1-1+10=0+10=10
1+10-1=11-1=10
-1+10+1=9+1=10
you do it left to right making it incorrect to do 1-1 first.
It’s NOT incorrect to do 10-1+1 or 10+1-1. It IS incorrect to do 10-(1+1), which is what you did
By doing it out of order and incorrectly I was able to make my statement true
It was solely because you did it incorrectly. Order doesn’t change anything.
did addition before subtraction instead of left to right
No, what you actually did was put it inside brackets, thus changing the number of terms. Doing addition first gives the exact same answer as doing subtraction first…
subtraction first 10-1+1=9+1=10
addition first 10+1-1=11-1=10
You did 10-(1+1), hence the wrong answer. It doesn’t matter which order you do it, though often students make mistakes with signs when they change the order, which is why we teach to do left to right.
No we don’t.
No we don’t. Just check out some final exams to see plenty of them still included.
Most teachers do, but some aren’t very good, especially in the U.S. where it’s not even required to have Maths qualifications to be a Maths teacher.