I am a 77 year old woman who had a couple of very intimidating math teachers in middle school so I never mastered algebra and have regretted it all these years. Thank you for your KZfaq channel. I watch it every night on TV and I am determined with your help to finally be able to conquer this and cross it off my bucket list. Thank you, John, for your patient teaching.

I have spent my life feeling stupid because I didn’t understand this stuff and now I realise that I just wasn’t taught the basics properly. I wish that I’d had a teacher like you, Sir! My life would have taken a completely different direction. This 62 year old thanks you very much!

Correction......."if we have both multiplication and division, neither has priority and we work from left to right". So the answer is 165.

3(5 + 20 / 2 x 5) brackets first .. and 20/2 first 3(5 + 10 x 5) then 10 x 5 3(5 + 50) then 5 + 50 3(55) then 3 x 55 165

Multiplication and division are of equal value and are done in the order that they appear in the equation from left to right; the same is true of addition and subtraction. It should be 3 x (5 + ((20/2) x 5)) = 3 x (5 + (10 X 5)) = 3 x 55 = 165.

I'm 60 and had never heard of PEMDAS or wasn't listening in class. But after 2 previous videos I've watched of yours, I got this correct! Shocked and proud of myself. I wish you were my teacher 45 years ago!

To solve this expression, you need to follow the order of operations (PEMDAS/BODMAS), which stands for Parentheses/Brackets, Exponents/Orders (i.e., powers and square roots, etc.), Multiplication and Division (left-to-right), and Addition and Subtraction (left-to-right). In this expression: 3 * (5 + 20 / 2 * 5) Let's break it down step by step: First, evaluate the expression inside the parentheses: 5 + 20 / 2 * 5 Now, follow the order of operations within the parentheses: a. Divide 20 by 2: 20 / 2 = 10 b. Multiply 10 by 5: 10 * 5 = 50 c. Add 5 to the result: 5 + 50 = 55 So, the expression inside the parentheses simplifies to 55: 3 * 55 Finally, multiply 3 by 55: 3 * 55 = 165 So, the answer is 165.

In the Netherlands, the answer would be 21. Unless they changed the rules. The formula in which order to solve this over here is (was?) Meneer Van Dalen Wacht Op Antwoord (literally translated Mr Van Dalen Waits On Answer) : Machtverheffen (not applicable here), Vermenigvuldigen (multiply, so 2x5=10), Delen (divide, so 20/10=2), Worteltrekken (not applicable here), Optellen (add, so 5+2=7), Aftrekken (not applicable here). So we end up with 3x the 7 from within the brackets, equals 21.

165. Depending on the country, the name of the order of operation may differ, but the concept is the same. I learned BEDMAS... Brackets, Exponents, Division and Multiplication, Addition and Subtraction.

42. The answer to everything in the universe .. except this. It's 165 3(5 + 20 / 2 x 5) = 3(5 + 10 x 5) = 3(5 + 50) = 3(55) = 165

Hello, I am British and we use BODMAS, eg Brackets, Of (to the power of), Division, Multiplication, Addition, Subtraction. Using this mnemonic means you don’t have to complicate the process further by having to remember to check on the order of the division and multiplication within the brackets. Division is always carried out first ie before multiplication.

Instead of PEMDAS I taught my students PEMoDAoS, the little "o" stands for OR, when confronted by the same level of operation the one that comes first working left to right (the same direction we read) is the one acted upon. I had the kids make up their own sayings to remind themselves, the best was "Perform Each Math Operation During Algebra On Schedule". When the kids become invested they own it!!

When i did math in the sixties the way this is written the answer would be 7.5 . We were taught to figure inside the parentheses first. 5*20 =25 divided by 2*5 =10 answer 2.5 *3 =7.5

I got 165 and did it in my head. I was lucky to get a really good education growing up. I guess it comes down to the luck of where you live and which school you get to go to. Thanks for sharing this lesson.

Another method to help you with PEMDAS (or confuse you more ;-) ) is keeping in mind that a **division is just a multiplication of the inverse value or reciprocal so that will transform your problem to: 3 ( 5 + 20 * 1/2 * 5 ) or 3(5 + 20*.5 * 5) , so now the division disappears and you do left to right multiplications in order first. 3 ( 5 + 10 * 5 ) => 3 * (5 + 50) , 3 (55) = 165 or when you are down to 3*( 5 + 50 ) , you could use the distributive principle you use in algebra of a (b+c) = (ab+ac); (3*5 + 3*50) = (15+150) = 165 to verify that you answer is right. Keep in mind that PEMDAS is just a trick for your to remember order of operations, but as you learn more math there are other tools that will help you gain speed or find easier ways to solve problems that might be more relatable on how your own brain works. This is fine example of how simple arithmetic is a foundation block for algebra, geometry, trigonometry, pre-calc + more. **Note: this is mostly true with integers and rational numbers, you run into some issues later in life in computing, software, with irrational and imaginary numbers like pi. :P

Appreciate this content! Wholesome, true, and even though I got 21 initially: you were not condemning.❤

I was taught Parentheses in order from left to right, then Exponents from left to right, then, Multiplication and Division in order from left to right, and finally Addition and Subtraction from left to right. Addition and Subtraction were equal in that you don’t prioritize one over the other and same with multiplication and division, you just do whichever appears first so 3x(5+20/2x5) 3x(5+10x5) 3x(5+50) 3x55 165 I’m really not a math fan, but my favorite math classes in school were business math and data analysis & statistics. To me they were fairly simple and the teachers I had were amazing. The business math teacher was a very kind and understanding professor who was very good at explaining it so that you got it the first time and he didn’t even make us get the book, he just read from his own and we all worked the problems out together. My data analysis and statistics professor didn’t make us get the book either and he actually introduced a lot of humor into his teaching style, but he had that really dark and sarcastic type of humor like mine, but he was never mean about it and genuinely cared about helping you learn. With the war on teachers in this country the last few years I really hope they haven’t been burnt out by it, especially since I live in a deep red, but northern red state.

Practical comment: As a 35+ year engineer… just use extra sets of parentheses. Or break it up into smaller parts. Or both. Other people may be looking at your work. Regardless of the correct “rules” it’s better to clearly communicate what you are doing … don’t assume that the other people know the rules as well as you do.

1) Divide 20 by 2 = 10 2) Multiply 10 x 5 = 50 3) Add 5 + 50 = 55 4) Multiply 3 x 55 5) Answer - 165

John, I love your math channel. I am a math person as well! Numbers & Math are the universal language. I think we should connect one day, I believe we would get along extremely well! Hope you channel continues to prosper!

I was taught PEMDAS (Please Excuse My Dear Aunt Sally) and got 165. 3(5 +20/2 x 5) = 3(5 +10 x 5) = 3(5 +50) = 3(55) = 165 Edit: I was taught PEMDAS in 6th grade and reminded again in Algebra

I love this!!! Back in college, I majored in math and I love solving problems so this was easy for me. Needless to say, my nieces and nephews and grandkids all call me when they need help with their math homework - because according to them, I explain it "way" better than their teachers can! However, trying to help them solve complex math problems over the phone is a pain - especially when I'm at work or at the grocery store! Because well, when solving any math problem, it's all about the visuals! Sadly, I'd say that 95% of people who think they're bad at math, really aren't. They've just never had the benefit of a great math teacher to visually explain the proper steps to follow when solving a problem. I tell my grandkids to always follow each step and that a single problem can take up to a half a page to solve, and extremely complex problems will take up the entire page - front and back! Knowing the proper steps and following those steps exactly, will ensure success. After watching your videos, I have to tell you that you sir, are a fantastic math teacher! Not only is your voice very calming, your visuals are the best I've seen! This is exactly the way I have shown my kids and grandkids how to solve a problem - only this is better! Your use of the green "chalkboard" style screen, combined with your use of fonts and explanation of proper procedure is extremely effective. It's so easy to understand, follow and comprehend. I just forwarded your channel to my entire family! The kids will be starting school in a couple weeks, so I told their parents to subscribe to your channel and to start watching one or two of your videos every day. I told them to make a game out of each video by having everyone solve the problem on their own, then watch the video to see who got it right! By turning it into a game, it makes it fun for the entire family and the kids (and parents) get a refresher course so they're prepared when they go back to school - creating an everlasting boost to their confidence. I'm so thankful I found your channel. You are a Godsend to both parents and kids who struggle with math! Your channel is a game changer! Thank you so, so much! 💙💯

Back when I was a child and dinosaurs ruled the earth, MD meant multiplication AND division, left to right; then AD meant addition AND subtraction, left to right. The answer would be 165.

7.5 was my answer..Making an error? That’s how I was taught how to do it…😢 never heard of PEDMAS. I probably should stay away from my son’s math homework.

Plus and minus come in which ever order they come first X and : come in which ever order they come first. In this, here is the 4 second easy calculation that ran in my head: 20/2=10 10x5=50 5+50=55 3x55=110+55=165

3[5+(20÷2)×5] --> 3[5+(10×5)] --> 3(5+50) --> 3×55 = 165

I was correct. All thanks to the tutoring my father, a civil engineer, gave me from grade school through college. God I miss him.

Got this one right, even though math used to be my worst subject ^-^ After getting a very bad grade at algebra, I started practicing it alot and actually started to enjoy it alot. Eventually I got one of the highest grades of the class and was alot of fun, like just making puzzles. Glad to see some still stuck ^^

Before watching the video: 20 / 2 = 10 10 x 5 = 50 5 + 50 = 55 3 x 55 = 165 [edit] And I was correct. I win... something. Probably.

I did that totally wrong by addition first and dividing the sum by the multiplied sum. 3(25/10)=7.5. That’s quite a difference. Thanks for reminding me of the order.

Maths is about clear expression. Define the problem in clear terms. Do not set out to confuse.

The critical clarifying moment that you presented here is the insertion of the simple word "OR" in the PEMDAS sequence. I don't recall ever hearing it simplified that way by any math teacher back in the day or in any other KZfaq presentations. I take my hat off to you in thanks, sir!

My lord if you were my teacher I would be great at math. Your voice isn't threatening and your teaching is superb. I commend you and I thank you for posting your knowledge and your spirit comes through to teach younger people and adults like myself how to properly understand math. I applaud you, your parents and all of your teachers. 👏🏿👏🏿👏🏿👏🏿🎉😊

It depends how in-depth you want to take it. The actual answer is 1 Look at the question ' what is first? ' of the 3 digit answer 165, the first digit is 1

Bing, 00:34 The expression 3 times ( 5 + 20 / 2 x 5 ) can be simplified by following the order of operations, which is parentheses, exponents, multiplication and division, and addition and subtraction. First, we solve the expression inside the parentheses by doing the division and then the multiplication. We get: 3 times ( 5 + 20 / 2 x 5 ) = 3 times ( 5 + 10 x 5 ) Then, we do the addition inside the parentheses and get: 3 times ( 5 + 10 x 5 ) = 3 times ( 55 ) Finally, we do the multiplication outside the parentheses and get: 3 times ( 55 ) = 165 Therefore, the answer is 165. If you want to check your answer or learn more about the order of operations, you can visit the following websites:

I'm 75 and terrible in math but I'm doing these to work my old brain. Thank you!

I am so excited! I got165! YES! I do not remember being taught this loooooong ago! (I remembered it from one of your previous videos, I think!). Thanks!

Delirious here. Got it right! You’re a great teacher, but I needed clarification and listened to another educator who said we always move from left to right and m/d means either procedure , but if division comes first, do division.. you’re good, thank you! Wanna give us some homework?

Fun idea. Remove all divisions with reciprocal multiplication. 3(5+20×0.5×5) makes way more sense 😊

You can see in the comments exactly why the International Organisation of Standardisation exists and why specifically ISO-80000-1 exists. It says when writing division on one line with multiplication or division directly after that brackets are *required* to remove ambiguity. Never write 20÷2×5 It is (20÷2)×5 or 20÷(2×5). Those are acceptable. Many are taught M is higher priority than D and some books do use that convention (and I don't just mean for multiplication by juxtaposition specifically) and that leads to the general mistake of 20÷2×5 = 20÷10. Avoid the mistake by writing properly on the first place. Use two line fractions as these are best practice.

I didn't enjoy math in high school, but I only had basic business math. When I stated college part-time, I had to take pre-algebra and learned to love quadratic equations. BUT outside of school and the fields of science and engineering, does this truly matter. I must say that after taking my math classes required with my degree, I never needed to use it again.

I follow BIDMAS (Brackets, Indicies, Division, Multiplication, Addition and Subtraction) If you come across (Multiplication and Division) do them left to right regardless If you come across (Addition and Subtraction) do them left to right regardless If you see numbers together with no sign multiply them. Would love to know if any of that is wrong every day should be a learning one. 20 / 2 = 10 10 x 5 = 50 5 + 50 = 55 3(55) is the same as 3 x 55 = 165

I have been a machinist and a fabricator and a carpenter in my lifetime and I’ve never run up on one situation where I used any equation like this. I couldn’t figure out in school why they were teaching me this and now I’m 52 and still don’t know why.

This is the first video of yours that I have seen, and I WILL be subscribing just to try and re-learn what I've forgotten from 9th grade Algebra I in 1973. I struggled with math beginning in 4th grade. Our teacher was Asian, his IQ was probably at least 200, the whispers in my class were that he could make a perfect circle on the chalk board, and they were right. His accent, his IQ, and the speed of what he wrote on the blackboard was faster than I could understand, and he didn't repeat things. That was my first year of fractions, and with each year after that, I struggled so hard, and when it was time to sign up for classes in 9th grade (still junior high) for math, there were 2 options. General Math or Algebra I. That was an easy choice for me, General Math. On day 1, I was nervous and happy all at the same time because I felt like it was something that would be easy for me. Sort of like some of my other classes were. My teacher was probably around the age of 60, and very easy to pay attention to. After day 2, he asked me to stay after class, and I was petrified. I went to his desk as the class emptied, and he asked me "why did you sign up for this class"? I hung my head (I was terrified of my own shadow) and told him of my difficulties with math and that I thought I would do better in General Math. He then told me that he also taught the Algebra 1 class, and he was sure that I could do it, and he wanted me to give it a try, and if I couldn't do it, I could go back to the simpler math. Having him tell me that he thought I could do it was something I wasn't very used to hearing, but I went to Algebra I the next day and I stayed in his class, never getting below an A- on anything. I was even raising my hand to answer questions-that was new for me also. That man made me believe in myself more than any other person in my life including my parents. So for High School, I joined my classmates in Algebra II. Totally different teacher, and I fell behind quickly. I barely got through the semester without failing, I dropped it after that first semester, and never took another math class. Little did I know how much math would be part of my life for 18 years of working in Ophthalmology. It was only dealing with positive and negative numbers, but I could rattle those numbers off, I had a great understanding of how crucial my numbers were for the surgeons, and while I never needed Algebra II, I climbed the ladder to the top rung one step at a time, always grateful for that one teacher who believed in me. Sorry for the book, I will sub you now that I've learned something from you. Your voice is calm just like my teacher who I wish I could have thanked for what he did for a farm girl who didn't think she would go far in life, but I did. God bless good teachers everywhere.

Since multiplication and division have equal weight, I did the 20÷2×5 part from left to right to reduce that to 50. Then I added 5 to the resulting 50 inside the parentheses to reduce that to one term, 55. Then just multiply the 3 on the far left by that. The answer is 165.

The world (and KZfaq) really needed another PEMDAS video

I was never taught any of this and got 187.5. Thank you for the lesson!

I got 165 too, we were taught BODMAS at school. Brackets, orders, Division, Multiplication, Addition, Subtraction.

BODMAS Brackets Division Multiplication Addition Subtraction 20/2=10x5=50+5=55x3=165

Basic computing: from left to right 1) multiplication 2) division 3) addition 4) subtraction. Work inside parentheses first.

*At 66 years old, it's never too late to re-energize one's brain, thank you, professor!* 👍

Learned PEMDAS from you yesterday and solved this one quickly!

I am 73 freaking years old and absolutely LOVE mathematics! When I had knee replacement surgery, there was a LOT of bed rest! I bought an algebra book and just worked problems, progressively more difficult, hour upon hour! I really enjoyed those weeks!! Love your method of teaching!

Wow, your videos have shown me exactly where I stopped learning math around the eighth grade. (Where I was still getting in trouble for working the problems in my head.) I never learned PEMDAS, but it was not for a lack of people trying to teach me. I just didn't much care about school. Not knowing PEMDAS must be what doomed me to failure in pretty much all higher levels of math, I somehow passed algebra one, parts one and two, in ninth and tenth grades. I failed algebra two as a junior, and took geometry, (which I actually enjoyed and did well) as a senior. This is the third video of yours I've watched now, and the first one which I was able to answer correctly!

You can also use the distributive property to convert the equation to 15+60÷6×15 = 165

Thank you teacher! I'm a frenchman of 71. I never heard about PEMDAS or equivalent in french before you spoke about it! And though my english is far to be perfect, i understood your whole explanations and i'm very glad of this. I have to precise that when i was young, i hated mathematics and the teachers in this discipline. Now i notice that i understand very easily, and in english! So i have to consider nowadays, that i am a little bit smarter than a nut... What a great satisfaction !😊😉

That's interesting. When I was in school in NZ we were taught BEDMAS (Brackets, exponents, division , addition subtraction). Which is slightly different to PEMDAS. But then if MD and AS are equal and you go left to right in that PEMDAS instance it doesn't really matter which you use, I still got the right answer of 165.

165 (20/2) = 10 10 * 5 = 50 50 + 5 = 55 (calculated inside the parentheses first with multiplication or division read left to right first come first serve) Then 55 * 3 Even though the multiplication math operator is missing from the written equation it is in the written text. 165 is answer

I learned BEDMAS back in the day. Brackets, Exponents, Division, Multiplication, Addition, Subtraction. 👌

I am actually quite proud of myself. NO ONE could ever make math make sense to me in school; At first I solved it incorrectly but as soon as I saw it written with a proper division sign opposed to the forward slash, which I also recognized as divide; I knew to do the division before the multiplication and got it right. And all in my head. Major accomplishment for me!!😀 I'm quite sure I couldn't pass a grade 8 math exam though....

I'm going back a long time now, roughly 37 years but I was taught bodmas, meaning B. brackets O. of D. division M. multiplication A. addition S. subtraction. Which would be a completely different answer due to a different process. So with all that said are you telling me that I was taught wrong.

A divide sign means invert the next expression and multiply, so first the equation is rewritten 3(5+20x 1over2 x5) The correct procedure is to eliminate all divide signs first. The rule of maths is - you can rewrite any expression as long as you don't change its value. In this case divide by two has the same value as multiply by a half. Be extremely careful using PEDMAS, BODMAS or derivatives there of, it's incorrect and incomplete. Concocted by someone who thinks they can solve string calculations without understanding syntax and nested formulae.

Sure wish you were my math teacher back in the day. Now I lament that I can’t do math and my brain cracks. I enjoy your videos. I don’t feel that I am not capable. Thanks.

I think some people get confused about the MDAS part. That means that Multiplication/Division are on the same level as well as Addition/Subtraction. They are worked right to left-M/D or D/M first-depending how the problem is written. That’s what tripped me up when I first started doing these types of problems.

since / and x and inside () is first it should be kinda read done like this.. 20/2 = 10, 10 x 5 = 50, 50 + 5 =55 and lastly 55 x 3 = 165

I didn't have a good math teacher until my freshman year in college. For years I had struggled with math, although I had the GPA I needed to be accepted by the university. This one professor cleared up the mystery...from that class onward, the rest of my classes were a snap! My 8th grade math teacher was also helpful, but I still had headaches with math. My freshman math prof made all the difference.

Thank you, I was never taught PENDAS. Graduated in 1982, I’m learning it now on KZfaq. I thought it was set in stone. I’m happy to know that it’s not. Thank you for this information.

I’m 61…(gasp) and someone along the way, taught me this…but I didn’t retain it. Today because of your video, I believe I got it! Pemdas! Love it…thank you.

My maths teacher used to shout at our class and I ended up hating maths because I just didn't understand and was scared to ask. It's so nice seeing and hearing examples like this, it makes me realise just how diabolical our teacher was.

to LIvingRoom TV who wrote, Nobody tell her this isn't algebra......this is just the sort of condescending attitude I faced all those many years ago but now I'm old enough not to have a poor self esteem about not learning algebra. Instead I feel empowered to learn math because of having KZfaq. When I was only 14 we didn't have the internet. We actually had to go to the library to find material to write a paper, go on a road trip with a paper map.....my husband and I drove all the way around our great country two times and we didn't have or need GPS. Anyway LivingRoom TV, I know the sample shown wasn't algebra....I'm learning basic math over again since it's been over 60 years since I took a math class. Give me a break! At least I'm determined to learn it and John is a great teacher. I only wish I'd have someone like him for general math instead of a Marine DI. You should be ashamed of yourself putting down an elder person. Have you no respect???

Whenever I'm in doubt in cases like this, I convert the divisions into multiplications. So it would be : 3 ( 5 + 20 x ½ x 5) = ? With that, the mistake that leads you to 21 can't happen. 20 x ½ x 5 = ? 10 x 5 = 50 -- or -- 20 x ½ x 5 = ? 20 x 2.5 = 50 -- or even -- 20 x ½ x 5 = ? 100 x ½ = 50 This approach also creates some freedom to choose the simplest calculation.

An alternative way, which still honors PEMDAS is to distribute the 3, thereby removing the parenthesis in one step. 3(5 + 20 / 2 x 5) --> 15 + 60 / 6 x 15 Then follow PEMDAS just like he shows for the rest: 15 + 10 x 15 15 + 150 165

From left to the right. First operations in brackets and point befor line operations. We dont use the cross for multiplikation. We use a single point. Division we dont write the line in between the points.

The problem with PEDMAS or BODMAS or any other pnuemonic used for order of operations, there are times when parenthesis should be utilized to eliminate ambiguity whenever possible since algorithmns will vary given the slight differences in the order of operations computing methods.

But to avoid confusion you would always add extra brackets if you are a good communicator.

I was part of the 21 answer crowd, unfortunately, but I’m grateful this video explained why I was wrong and how to not make the same mistake again. Thank you. I liked and subscribed.

Not reading comments. 21. Rule. Multiply before divisions. Solve parenthesis first is a definite rule.

What's wrong is writing the equation ambiguously like that. If I caught my school pulling that crap on my kid's test I'd sue their asses.

We learned these 3 simple rules since elementary. 1. Left to right 2. If there are parentheses, do them FIRST. (Left to right) 3. Multiplication OR Division FIRST but ALWAYS remember rule 1, LEFT TO RIGHT. I hope those SIMPLE rules helped a bit. ☺️😉 3(5+20:2x5) 3(5+10x5)... parenthesis first, Division/multiplication first, left to right ALWAYS 3(5+50) 3(55) 3x55 165 😊👍🏾

I just reduce the "dificulty" of the mnemonic by using more brackets to make more groupings. In this case, I would do something like this: 3(5+20/2x5) Becomes: 3(5+((20/2)x5))) Then I just solve the brackets from the inside towards the outside. 3(5+(10x5)) 3(5+50) 3x55 165 This is how it makes the most sense to me.

Even is the US, the order of operations, even when using PEMDAS, is not universally taught. Some teachers say multiplication goes before division and addition goes before subtraction without regard to left-to-right. Which is right depends on whom you ask. Confusing.

165 The real trick, is that division is not an operation, it's actually a multiplication by the inverse, and the inverse of 2 is 1/2 or 0.5, and the actual operation is 3(5+20x0.5x5).

I've got to review all of this stuff since I have a four year old grandchild that is exceptionally bright and all to soon he will be wanting to learn. In my view this guy is just what the doctored ordered. I don't know that he would agree but I've found that fifty per cent of learning Algebra on up is just learning the formula!

I had a lot of maths at secondary school about 45 years ago, in Poland. According to the rules we used back then, the correct answer would be 7.5.

It concerns me that on some other ‘Math KZfaq’s’ they have Engineers (Chem, Nuke, Elect, etc) that totally disagree with PEMDAS Method. PEMDAS is the first thing I’ve ever been able to grasp. Please Help 😮😢!

The other correct way is to use the transitive property with the paratheses. So 3(5+20/2*5) = 15+60/6*15 Then finish with the MDAS. 15+10*15 = 15+150 = 165

.... so... i did this via algebra expansion... 3(5+20/2*5) becomes (3*5) + (3*20) / (3*2) * (3*5), becomes 15+60/6*15, becomes 15+10*15, becomes 15+150, becomes 165.... Completely different method of dealing with the brackets but the same ultimate answer :)

According to the rules taught in German schools: 6/2(1+2) = 1 parentheses, exponents, IMPLIED MULTIPLIKATION, multiplication, division, addition, subtraction 6/2(1+2)= 6/ 2(3) = 6/ 2*3 = 6 [fraction bar] 2*3 = 6/6 = 1 I calculated it with a calculator prescribed by the German school authorities. TI calculators are banned in German schools because they calculate according to PEMDAS CASIO pocket calculators are required in German schools because they calculate according to PEJMDAS: 6/2(1+2)=1 Yes, MDAS is still used up to the 4th grade, but when higher mathematics is taught, PEJMDAS is normal

I had one instructor who told us from the start that on the tests, all 3 or 4 possible answers (on a multiple choice test) were possible but only one was correct (meaning he did what you mentioned and figured out all the ways people could do the problem wrong so that short of a calculation error like 5 x 5 20, you'd almost always see your "answer" as an option, but only those who were confident in what they knew, knew that they had the correct answer. On more complex problems this proved to be more frustrating and I obviously got some wrong because of minor mistakes, particularly as you get into more complex subjects like Calculus.

You didn't explain why PEMDAS isn't Followed.

Yep. I got 21. I went into denial. Then frustration. Then acceptance. Then I agreed with you. It's 165. LOL 😂

I always used the acroymn called BEDMAS. B for brackets, E for Exponents, then division, multiply, addition and finally division

Remembering the rules of pemdas and not overthinking it, I came up with 165 in my head in about 20 seconds. I’ve noticed people forget that addition and subtraction are equal, as are multiplication and division.

My problem is that (I THINK), when I learned Please Pardon My Dear Aunt Sally = PPMDAS = Parentheses Powers Multiplication Division Addition Subtraction AND That I was told (Again: To the best of my recollection) that Mutiplication PRECEDED Division even over left to right. That would give me the answer 21. BUT Those who are NOW saying that left to right has precedence are actually doing: PE(MD)(AS), which -- I'm sorry to say -- is NOT what I THINK we were taught back in the 60s

If you follow the order of operations, it’s pretty clearly 165. The issue is that the way the equation is laid out is needlessly confusing. All confusion can be avoided by simply using fractions for division in place of the division sign

I'm 59 now. Math has always been my strong suit! I did not know the technical word for the order of operations, but definitely knew how to calculate the correct answer (of 165). My curiousity, in regards to all of the people who came up with the correct answer, is wondering how many of you were able to solve the question within your head (i.e. not using pen/paper; calculator; etc.)?

OPERATIONS A linking of elements within a set and resulting within that set for all elements of that set is an operation. There exist monary, binary, trinary, … linkings. In mathematic: +,-,•,: are binary operations within the set of rational numbers. As soon as you introduce radical you enlarge the set to the irrational numbers. R and I build the real number set. Here you have the operators +,-,•,:,exp,log. Notice that the introduction of PI, e can not be generated by using operators. Those numbers are transcend. There are exactly 11 AXIOMS which define the set of real numbers. The set is called FIELD.

We were never taught PEDMAS. Using parentheses and brackets eliminated any confusion about the sequence of operations. That’s why it had to go.

for 165: 3[5+5(20/2)] or simply 15+15(20/2)] and for 21: 15+[{3x20)/(2x5)] or simply 15+6. The only reason to see such is on a test, revealing exam writers ability for presenting inane questions.

For someone that has had difficulty with understanding basic algebra. This is the third video I watched and ta da. I got it right. Woo hoo. Thank you.thank you,thank you.