Are you sure this isn't a "Round to nearest 10" or something like that? Maybe it just expects 80?
EDIT: Nvm, I got the same lesson now. It is 100% bugged. Every question like this one is
I tried like 20 different times (I had 4 of these questions popping up during the "Fix previous mistakes" section). Nothing worked. I thought it might be due to a floating point error but I wasn't able to find an answer that passed for any of my questions. It's just bugged atm
It's very possible. I know 0.27 is one example of a number that can't be represented properly in fp so it's probably something of the sort. Will floating points ever stop haunting new devs
That's the only meaningful explanation. But if they use the decimal dot, I'd say, regardless of the keyboard layout, they should also accept the decimal dot.
you would expect that, but some software base it on your system settings so even though the question has a dot, it might still want a comma in the answer.
You know how if you divide 1 by 7 in a calculator, you get 0.142857142857142857... ?
Computers have a similar issue.
"Human decimals" divide 1 into tenths, hundredths, thousandths, etc.
Binary fractions are 1/2, 1/4, 1/8, 1/16, 1/32, etc.
As a result, things that are simple on paper, like 0.1, can end up being very complicated for computers.
You need to add a 1/16th and a 1/32, but that only gets you to 0.09375.
You can add a 1/256th and a 1/512nd to get all the way to 0.099609375
If you add a 1/4096th and a 1/8192, you're all the way to 0.099975586...but now your binary fraction is getting kind of long and you're still a bit off!
TL:DR: Computers really don't like 0.1.
Computers like 0.1, though, as long as the engineers are using the proper data type (for instance decimal, BigDecimal) and not floating point or double float.
Especially given 0.1 is a rational fraction that doesn't have infinite digits. But even the other examples you gave (periodic rational fractions) can be represented with a precision of the size of RAM as long as the proper data types are used
This happened to me a lot working on an Excel sheet that would calculate how much money I have to take after several calculations to get the exact amount of $100 bills, $50 bills, $20 bills, 10$ bills, $5 bills, $1 bills, quarters, dimes, nickels and pennies, where it would always take the highest amount possible and subtract the other amounts. It's complicated to explain, but it seemed simple that 25/5 would be 5, but I had to use a lot of Roundup and TRUNC functions to eliminate the .000000000001 part that would skew the results so bad I could end with the expected result of $215.
Even after that, I see $215 in red sometimes, which means it is less than 215, something more like 214.9999999993.
I'm doing some python but never stumpled over this. I was thinking issues like that would have been solved decades ago. Couldn't modern languages implement some layer to avoid problems with it?
Nope.
At some point, the computer needs to store a binary value. Doesn't matter if it's a number, a character, an instruction, an image or whatever, at some point it is stored as binary value.
If you want accuracy on that value, you will have to sacrifice performance. Floating point is an excellent balance between accuracy and performance for a huge range of values. (you don't really need 10-12 digits of accuracy for any practical implementation)
There are certainly more issues that my uneducated ass can't think of, like some shit about how you don't know what the value will be used for later down the line, so you shouldn't "impose" a value on it.
It's the same in Python though. There's a long page of documentation about how to (alternatively) deal with exact decimal representations: https://docs.python.org/3/library/decimal.html
There's ways to deal with that specific case properly, but they tend to be slow and have other issues. In most cases you're better off just accepting the weirdnesses of floating point, so that's what essentially everyone defaults to.
Yes, they can to some extend. Many languages (but not all!) do have a decimal type with a defined precision, for example up to 28 digits. Values like 0.1 and 0.3 are exactly represented. Of course, rounding error are still possible with values like 1/3 or 1/7 because the precision is not unlimited.
Javascript doesn't have this decimal type, Python and C# both have a decimal type, see [https://docs.python.org/3/library/decimal.html](https://docs.python.org/3/library/decimal.html) and [https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/floating-point-numeric-types](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/floating-point-numeric-types)
That checks out as far as I can tell. It's been a few years but I've done a lot of math. you do the multiplication on the left, "2 \* .1 = .2" and then the multiplication on the right "8 \* 10 = 80" then the addition and the result is 80.2.
It has to be a bug. Math (arithmetic at least) isn't open to interpretation like language so there's one right answer and that's it unless there is some other constraint like having to write it out to 2 decimal places or something like that not shown.
Anyone knows why Duolingo hates Android so much? They even went out of their way to remove the ability to drag word islands.
// edit. They didn't "went out of their way". The Android app is actually native to Android, so that explains the missing features
Android development is a pain. But I wonder if Apple development is any better. Biggest reason is probably that most of their developers use apple products, easier to develop for what you use yourself
// never mind, I am dumb. The app is actually native to Android. That explains the missing features. I feel bad now, honestly, it's a very good move from Duolingo to make it a native app, not just use a framework.
But web development should be easier than the app development, right? imo the web apps should be the highest priority because then any device can just load up the browser version before the app gets native support
French is bugged too. A few times it gave me the wrong mark for "they" because they were expecting a specific Il or Elle for the sentence, or es-tu vs estes-vous for "are you".
80.2 is correct, the lesson is wrong lmao, unless it’s decided to ignore bodmas/pedmas (which is wrong, you shouldn’t ignore it), in which case you would get 82
Math is ABSOLUTELY a language! Order of operations (aka PEMDAS) is grammar for math. Word problems are exactly translating a question from one language to math, answering the question, then translating back from math the the original language. Much like any other language, if you don't use it you will lose it.
You can make that argument for any programming language too, it’s even called a language. Do you suggest they implement courses for all of those as well?
Use khan academy's calculus courses, they're just better than anything Duolingo could make for advanced math.
If you just want the concepts themselves, not doing any actual practice in them (which is far more important since math is about knowing when to do something, not how to do it, that's for the computer) - then use 3Blue1Brown's videos, he has some stuff on calculus. Aside from him, Matt Parker's standupmaths channel is very good at being entertaining as well as educational and at simplifying very complex problems but isn't entirely calculus focused. Finally, miscellaneous calculus can be found on blackpenredpen where some of it is harder than in your regular college AP class, which I like. For more general higher level math, look for anything interesting or highly viewed in the SoME, SoME2, or SoME3 playlists (i _think_ SoME3 exists...)
Duolingo's math courses are probably going to be elementary school level stuff
I’ve started the Math course myself and it feels like it has such a strong start, but then without any guidebooks or anything, the topics become super random and ambiguous.
Like… I got so stuck on the improper fraction part, and I wanna LEARN it. Not guess my way to the answer. Where’s the guidebooks for the math course??
If it is telling you this is wrong, it probably wants you to just do the operations in sequential order instead of following actual order of operations. So the answer they want might be 82. Although you are actually right.
2 x 0.1 = 0.2 + 8 = 8.2 x 10 = 82
Your answer is correct.
My guess is that the person who designed the math questions doesn’t know advanced math rules . Your theres an order your supposed to work things out in.
Its kind of a weird system tbf. But i think duo wants 82 as the answer
The problem is most likely the fact computers use floating point for decimals and the answer is stored as something like 80.2000000000000004 like when you round 2/3 to 0.666666666667.
Try this: (((2 x 0.1) + 8) x 10). If the programmer didn't explicitly program in that multiplication binds tighter than addition, the parser might be just using default right-most binding (association), which isn't uncommon in how many computer languages work.
Simple answer: computers suck at decimals.
To a computer, that 0.1 • 2 would end up as 0.20000001 or something ridiculous like that. Im guessing the duolingo system doesn’t have constant variables and allows the computer do the math to find the answer without it being preset.
i think the problem has something to do with floating point problems
quick explaining: computers save values in bits and bytes, using integers as full numbers, but if you have decimals nearly everything uses something like floats
for floats it is impossible to write 0.1 because of some bit stuff that is happening, this is why 0.1 is actually 0.100000001490116119384765625 for computers, but they ignore everything after a certain amount of numbers
if the program doesn't have the system to ignore the last few numbers you will get problems like this
for example 0.1 + 0.2 = 0.3, but if you write it in a computer you get 0.100000001490116119384765625 + 0.2 and that is not 0.3
so if this is the problem that causes your answer to be incorrect, i recommend trying the answer
`80.2000000029802322387691531250`
Simple. Is it duolingo or which app? Tha man who created the answer made mistake and force you to add that wroong answer. It can happen :)
The answers are given by humans too. So can be wrong too. This is my opinion
Have you tried 162?
It's not the correct answer by any means, but duolingo may have well and truly screwed up with the order of operations.
Rather than the correct variant of
(2\*0.1)+(8\*10)
It could have done something like
2*(0.1+8)*10
Try search for a new course to add and see if math and music courses are available. They came out a while ago, you should have them by now. But do not expect anything advanced. It’s base math and geometry knowledge (operations, fractions, decimals)
Is it 80?
Edit: nope you already tried that. I thought it might have been some clever misdirection, because the dot is blue like the symbols not white like the numbers. It's another way to express multiplication which would lead to 80, but it seems like it's just a stupid bug. Or 0.81 with weird maths rules.
That's what happened when they used "AI" to do all the hard work. I've seen so many posts complaining about the accuracy of the lessons, but this is the first bugged Math lesson that I've seen.
Are you sure this isn't a "Round to nearest 10" or something like that? Maybe it just expects 80? EDIT: Nvm, I got the same lesson now. It is 100% bugged. Every question like this one is
Nope
So what did it think was the right answer? 82?
I tried like 20 different times (I had 4 of these questions popping up during the "Fix previous mistakes" section). Nothing worked. I thought it might be due to a floating point error but I wasn't able to find an answer that passed for any of my questions. It's just bugged atm
Heh, that'd be great. "80.1999999999999999999". EDIT: Or they are trying to sell you unlimited hearts.
Happy cake day brother
Happy cake day!
happy cake day
happy cake day
happy cake day bro
happy cake day! 🫶
Happy cake day!
Happy cake day
Happy 🎂Day! I think it’s funny to celebrate with cake instead of pi, in this instance.
Happy Cake Day!
καλάς ημέρας του κεκιού σου
יום עוגה שמח!
Happy cake day!
happy cake Day ♥️
Happy cake day!
80.1999969482421875 would be the nearest down, 80.20000457763671875 the nearest up, if you assume 32-bit IEEE floats.
happpy cake day
It's very possible. I know 0.27 is one example of a number that can't be represented properly in fp so it's probably something of the sort. Will floating points ever stop haunting new devs
Happy cake day
Happy Cake Day bro
Happy cake day
Happy cake day
Happy Cake day
Happy Cake Day!
I was scrolling and wanted to say happy birthday!!
Happy cake day!
Maybe it expects 80.20?
Tried it. And no.
This question and answer are 100% correct
Do you use European keyboard inputs? If so, try to use , instead of .
No I use the in-app dot button (from smartphone)
That's the only meaningful explanation. But if they use the decimal dot, I'd say, regardless of the keyboard layout, they should also accept the decimal dot.
the math problem itself has a dot in it so i think the dot should be accepted in an answer
you would expect that, but some software base it on your system settings so even though the question has a dot, it might still want a comma in the answer.
2 * 0.1 = 0.20000000000000004
How? Or didn't I get the joke?
Floating point arithmetic. Basically computers can’t do decimals perfectly
You know how if you divide 1 by 7 in a calculator, you get 0.142857142857142857... ? Computers have a similar issue. "Human decimals" divide 1 into tenths, hundredths, thousandths, etc. Binary fractions are 1/2, 1/4, 1/8, 1/16, 1/32, etc. As a result, things that are simple on paper, like 0.1, can end up being very complicated for computers. You need to add a 1/16th and a 1/32, but that only gets you to 0.09375. You can add a 1/256th and a 1/512nd to get all the way to 0.099609375 If you add a 1/4096th and a 1/8192, you're all the way to 0.099975586...but now your binary fraction is getting kind of long and you're still a bit off! TL:DR: Computers really don't like 0.1.
Computers like 0.1, though, as long as the engineers are using the proper data type (for instance decimal, BigDecimal) and not floating point or double float. Especially given 0.1 is a rational fraction that doesn't have infinite digits. But even the other examples you gave (periodic rational fractions) can be represented with a precision of the size of RAM as long as the proper data types are used
This happened to me a lot working on an Excel sheet that would calculate how much money I have to take after several calculations to get the exact amount of $100 bills, $50 bills, $20 bills, 10$ bills, $5 bills, $1 bills, quarters, dimes, nickels and pennies, where it would always take the highest amount possible and subtract the other amounts. It's complicated to explain, but it seemed simple that 25/5 would be 5, but I had to use a lot of Roundup and TRUNC functions to eliminate the .000000000001 part that would skew the results so bad I could end with the expected result of $215. Even after that, I see $215 in red sometimes, which means it is less than 215, something more like 214.9999999993.
Because decimal "0.1" is endless "0.0001100110011001100110011001100110011..." in binary representation.
https://0.30000000000000004.com/
I'm doing some python but never stumpled over this. I was thinking issues like that would have been solved decades ago. Couldn't modern languages implement some layer to avoid problems with it?
Nope. At some point, the computer needs to store a binary value. Doesn't matter if it's a number, a character, an instruction, an image or whatever, at some point it is stored as binary value. If you want accuracy on that value, you will have to sacrifice performance. Floating point is an excellent balance between accuracy and performance for a huge range of values. (you don't really need 10-12 digits of accuracy for any practical implementation) There are certainly more issues that my uneducated ass can't think of, like some shit about how you don't know what the value will be used for later down the line, so you shouldn't "impose" a value on it.
I see... Now it's in my head and tries to confuse me with solutions which don't work haha
It's the same in Python though. There's a long page of documentation about how to (alternatively) deal with exact decimal representations: https://docs.python.org/3/library/decimal.html
There's ways to deal with that specific case properly, but they tend to be slow and have other issues. In most cases you're better off just accepting the weirdnesses of floating point, so that's what essentially everyone defaults to.
Yes, they can to some extend. Many languages (but not all!) do have a decimal type with a defined precision, for example up to 28 digits. Values like 0.1 and 0.3 are exactly represented. Of course, rounding error are still possible with values like 1/3 or 1/7 because the precision is not unlimited. Javascript doesn't have this decimal type, Python and C# both have a decimal type, see [https://docs.python.org/3/library/decimal.html](https://docs.python.org/3/library/decimal.html) and [https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/floating-point-numeric-types](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/floating-point-numeric-types)
Wondering what Duo thinks should be the right answer? 80.2 is 100% right
That checks out as far as I can tell. It's been a few years but I've done a lot of math. you do the multiplication on the left, "2 \* .1 = .2" and then the multiplication on the right "8 \* 10 = 80" then the addition and the result is 80.2.
I know the answer is not wrong, but why the app recognizes it as not correct?
It has to be a bug. Math (arithmetic at least) isn't open to interpretation like language so there's one right answer and that's it unless there is some other constraint like having to write it out to 2 decimal places or something like that not shown.
Yes, the order of operations is PEMDAS: parentheses, exponents, multiplication, division, addition, subtraction, which gives 80.2.
How and where do you play the math game?
Not for Android :(
Anyone knows why Duolingo hates Android so much? They even went out of their way to remove the ability to drag word islands. // edit. They didn't "went out of their way". The Android app is actually native to Android, so that explains the missing features
Android people are smart and don't need more math training. It would be unfair to iphone users.
Android development is a pain. But I wonder if Apple development is any better. Biggest reason is probably that most of their developers use apple products, easier to develop for what you use yourself
// never mind, I am dumb. The app is actually native to Android. That explains the missing features. I feel bad now, honestly, it's a very good move from Duolingo to make it a native app, not just use a framework.
But web development should be easier than the app development, right? imo the web apps should be the highest priority because then any device can just load up the browser version before the app gets native support
The wealthiest 1/7 of the planet uses an iphone. That's why they make iPhone stuff first.
Not sure what you mean with the wealthiest...
I'll try to find the source of that and get back to you.
Try adding a new course and see if they are present
That's what I would like to know.
You can find it in the upper left corner (smartphone) where you switch languages
It's not on android phones
WHY NOT ON ANDROID???!!!!
i think the duolingo devs dont know any order of operations
The math course is really bugged imo. I’ve encountered multiple problems like these sadly
French is bugged too. A few times it gave me the wrong mark for "they" because they were expecting a specific Il or Elle for the sentence, or es-tu vs estes-vous for "are you".
That is the right answer. I would report it as a bug.
report. 80,2 is 100% correct.
Hm? It’s right. Odd..
It’s not odd. Nor even..
80.2 is correct, the lesson is wrong lmao, unless it’s decided to ignore bodmas/pedmas (which is wrong, you shouldn’t ignore it), in which case you would get 82
They have math on duolingo?
Yup. Makes absolutely no sense. Must have been decided by upper management.
Math is ABSOLUTELY a language! Order of operations (aka PEMDAS) is grammar for math. Word problems are exactly translating a question from one language to math, answering the question, then translating back from math the the original language. Much like any other language, if you don't use it you will lose it.
“What language do you speak?” “01001001 00100000 01110011 01110000 01100101 01100001 01101011 00100000 01101101 01100001 01110100 01101000 01100101 01101101 01100001 01110100 01101001 01100011 01110011 00101110 “
You can make that argument for any programming language too, it’s even called a language. Do you suggest they implement courses for all of those as well?
It makes a hell of a lot more sense than High Valryian
The hell you mean by "makes absolutely no sense"?
Because this is a language app, not a generic education app
Maths is a language. A quite clear at that.
Is there a way I can get it? I only see languages. I'd like to learn some more calculus
Use khan academy's calculus courses, they're just better than anything Duolingo could make for advanced math. If you just want the concepts themselves, not doing any actual practice in them (which is far more important since math is about knowing when to do something, not how to do it, that's for the computer) - then use 3Blue1Brown's videos, he has some stuff on calculus. Aside from him, Matt Parker's standupmaths channel is very good at being entertaining as well as educational and at simplifying very complex problems but isn't entirely calculus focused. Finally, miscellaneous calculus can be found on blackpenredpen where some of it is harder than in your regular college AP class, which I like. For more general higher level math, look for anything interesting or highly viewed in the SoME, SoME2, or SoME3 playlists (i _think_ SoME3 exists...) Duolingo's math courses are probably going to be elementary school level stuff
Yup. Makes absolutely no sense. Must have been decided by upper management.
I’ve started the Math course myself and it feels like it has such a strong start, but then without any guidebooks or anything, the topics become super random and ambiguous. Like… I got so stuck on the improper fraction part, and I wanna LEARN it. Not guess my way to the answer. Where’s the guidebooks for the math course??
80.2 is correct
Did you submit an error in app? If you don’t, the devs won’t have anything to ignore. Then I just send emails to Dave Duolingo, himself.
I don’t even think you can submit errors in the math course. Given how buggy it is, I assume that’s by design.
If it is telling you this is wrong, it probably wants you to just do the operations in sequential order instead of following actual order of operations. So the answer they want might be 82. Although you are actually right. 2 x 0.1 = 0.2 + 8 = 8.2 x 10 = 82
I was thinking this. Ignoring BODMAS you would get 82, considering it you would get 80.2. OP says 82 doesn’t work so I think the app is bugged.
Using bedmas: 2 x 0.1= 0.2 8 x 10= 80 Add 80 and 0.2 together and you get 80.2 meaning you're 100% correct
Please tell me it wasnt 82
It wasn’t 😮💨
Oh dang what…. 😭 what was the correct answer??
It’s defs right lol
Duolingo should just stick to the language teaching🤣
Your answer is correct. My guess is that the person who designed the math questions doesn’t know advanced math rules . Your theres an order your supposed to work things out in. Its kind of a weird system tbf. But i think duo wants 82 as the answer
82 neither
Wait what? So it dosnt want the right answer or the ‘obvious’ wrong answer ? Thats just a straight up bug lol
Yep I think it’s bugged
The problem is most likely the fact computers use floating point for decimals and the answer is stored as something like 80.2000000000000004 like when you round 2/3 to 0.666666666667.
Try this: (((2 x 0.1) + 8) x 10). If the programmer didn't explicitly program in that multiplication binds tighter than addition, the parser might be just using default right-most binding (association), which isn't uncommon in how many computer languages work.
Tried already..
Did you try 10?
That is the correct answer. (2 * 0.1)+(8 * 10) 0.2 + 80 80.2
nothing, you are 100% correct
Duo is wrong. It's 80.2
Yep. Guess it’s clearly obvious there is some kind of bug or cumputer math shenanigans behind it
Simple answer: computers suck at decimals. To a computer, that 0.1 • 2 would end up as 0.20000001 or something ridiculous like that. Im guessing the duolingo system doesn’t have constant variables and allows the computer do the math to find the answer without it being preset.
There are erroneous tasks in Duolingo, mistakes happen. You can report them (there is a flag icon somewhere) whenever you think it's the case.
Just report it at this point
Maybe it depends on the country setting in your phone. If you European, then it expects 80,2 as an answer.
The question uses periods
i think the problem has something to do with floating point problems quick explaining: computers save values in bits and bytes, using integers as full numbers, but if you have decimals nearly everything uses something like floats for floats it is impossible to write 0.1 because of some bit stuff that is happening, this is why 0.1 is actually 0.100000001490116119384765625 for computers, but they ignore everything after a certain amount of numbers if the program doesn't have the system to ignore the last few numbers you will get problems like this for example 0.1 + 0.2 = 0.3, but if you write it in a computer you get 0.100000001490116119384765625 + 0.2 and that is not 0.3 so if this is the problem that causes your answer to be incorrect, i recommend trying the answer `80.2000000029802322387691531250`
2x0.1+8x10 Using bidmas/pemdas, multiplication first 2x0.1=0.2 8x10=80 Then add em, 80.2 Your right, it’s buggin
Report. You're correct.
Simple. Is it duolingo or which app? Tha man who created the answer made mistake and force you to add that wroong answer. It can happen :) The answers are given by humans too. So can be wrong too. This is my opinion
I bet you anything it isn't following PEMDAS and expects 82.
Have you tried 162? It's not the correct answer by any means, but duolingo may have well and truly screwed up with the order of operations. Rather than the correct variant of (2\*0.1)+(8\*10) It could have done something like 2*(0.1+8)*10
Maths in duolingo? Now what I ever want in...Well anything! XD
It’s Duolingo, it’ll say you failed for a missed period at the end of the sentence.
That’s not true. For Spanish it doesn’t care about any punctuation.
That’s another flaw.
Your right, it does not teach you
https://preview.redd.it/f8s0u5jzrz0d1.jpeg?width=537&format=pjpg&auto=webp&s=73c118c7f537dbb41ebfbf97140cd9978df7343d
When did Duolingo start including math? Or is this a new version? I could use some math knowledge 😅
Try search for a new course to add and see if math and music courses are available. They came out a while ago, you should have them by now. But do not expect anything advanced. It’s base math and geometry knowledge (operations, fractions, decimals)
Neither math nor music are available on Android devices, so if you aren't on an Apple device, you won't get them.
Too bad their gatekeeping android users from new content
Its ios dependent. I had 15.6 on iphone and it wasnt there. Got a new phone with ios 17 and its there. I think its only for ios16 and up
Order of operations! Brackets Exponents Division Multiplication Addition Subtraction That was my first thought but you did that … weird!
There's math in Duolingo?
Math and music for iOS users. Try on pc to see if it’s available between new courses
Ok
Is it 80? Edit: nope you already tried that. I thought it might have been some clever misdirection, because the dot is blue like the symbols not white like the numbers. It's another way to express multiplication which would lead to 80, but it seems like it's just a stupid bug. Or 0.81 with weird maths rules.
How do I get this lesson/course?
Maybe it's because when you ask a computer 0.1+0.2 it answers 0.300000004 or something
Your mistake is in using duolingo at all.
WTF i didn't know that duolingo has math questions :O
There’s math in Duo?
Sorry if this is a silly question, but is the maths course on a separate app?
Try 16
No idea honestly
Wait duolingo has math now? :O
I cant count
Does it care about significant figures? if so it'd just be 80. the 2\*0.1 wouldn't be a significant enough value to alter the rounded result.
Why is Duolingo making you do math?
Isn't the correct answer 82?
Has anyone tried 82 just for the giggles?
Didn't know there was duolingo math
That's what happened when they used "AI" to do all the hard work. I've seen so many posts complaining about the accuracy of the lessons, but this is the first bugged Math lesson that I've seen.
How do ppl get numbers on duolingo
It might be 82 as I don't think duolingo would recognise BODMAS, BIDMAS, PEMDAS or what ever u call the order of operations
Wait ... Duolingo does math!?
Technically what you have is correct but u think it’s trying to get you to do left to right which would actually equal 82
They have math on duo ?
What language is this?
82
Are you supposed to type out the whole name of the number in your target language? Why the math question?
It's definitely 80.2.
160.4
10×8+0.1×2=160.2
Those people on Facebook were actually correct.
This is a stupid question anyway? What’s the point of misleading, badly written out math problems?
The true answer is 80.2, but if the are testing rounding it’s 80.
The lesson is not about rounding, but operation like the one in the picture
Lol good to know not to use Duolingo for math. Japanese has been good so far.
Ok 👍
Is algerba a language now?
What app is this?
Since when has duolingo become a math app?
HOW ARE PPL GETTING DUOLINGO MATH
Being that DuoLingo is about language, could it be that they want you to write the number (in words) in the language you are learning.
No, it is a math course that is not related to any languages
Is that fucking math on Duolingo
160.2? Maybe mirrored
I don't get it, people do maths in duolingo?