This is exactly what I was looking for. I'm not in 8th grade, but I am preparing for a masters degree. (I wish I would have known in high school that I would need this later) :D
Hello, I'm an 8th grader whom just spent about 2 and a half hours fatorizing the number 225.then I finally got tired and looked on RU-vid to see if anything could help me. And this video did just that. Thank u so much u helped me a lot. God bless you ❤️🎉💕
That’s fabulous! I’m so pleased. My second vid on this has an example which has repeating primes. I think that might actually be a bit better - I was getting stronger with the method and the thinking. Doesn’t ‘guess and check’ just suck the life out of you? I loathe that approach and I love this one for its speed and clarity. 😃🤗🤩💕
@@LetsDoMath yah, I rly don't like the guess and check method. It takes too long. (and it is very irritating if I must say) but this is an organized method and I rly enjoy doing it. Thax again so much.
grade 10 and struggling with arithmetic geometric sequences because of lots of GCD and shenanigans. THANK YOU SO MUCH this helped clear what I was missing!!!!
hi!! advanced grade 6 level student here, this is literally the BEST method i know. Thank you so much!! gotta do homework now i am 2 days behind schedule and my class is tomorrow!!
Cool! I was delighted when I first thought of it and tried it out! That whole thing of taking anew line each time was just my way of keeping straight what I’d actually done first time.I was kind of surprised when it suddenly all came together! I’m glad you like it too, and thanks for your note. 🤗😃😎💕
Great stuff. The second one, with repeated prime factors is a bit stronger I think. Probably because I’d done a lot more practice with this strategy and was much more comfortable with it. In this first video, I’d only just come up with the method. Pretty exciting stuff though, to be able to suddenly get all those pesky factors, where previously, no matter how hard I tried, I’d miss at least a couple of factors. Now, that’s a thing of the past.
Glad you like it.,I was really happy when I worked it out. These kind of questions have always left me missing a couple of factors out. Not any more! 😉😎💕
After going through your video and working out the factors for 210, I tried working out a random number, 432. I'm confused with how this method works with a number such as 432. After prime factorizing I'm left with 2 to the power of 4 and 3 to the power of 3 and I'm not sure how that works to show me all the factors of 432. How would you work out 432?
I made a second vid on this method covering a number that gave repeated primes. That will help you. It’s in my playlist Factors, Prime Factors. If you go through my website letsdomath.ca it’s even easier to locate.
I ma in grade 5 and I was struggling on this kind of question.I am preparing for IMO SOF. IMO is impossible to do. This video helped me a lot. BEST VIDEO EVER
Thank you so so much for this, it helped me a lot! And Instead of being on my phone or any type of device all the time, i think i shouldve just studied. You made math even more easy for me, thank you so much!
They make phones enticing and engaging, probably too much so. It takes some willpower to put it face down, turn it off and do something more productive instead. Good for you, coming back to the math with solid purpose! If you put in regular practice at solving problems, you'll really see the benefit quickly - in terms of how quickly you think through a problem, and the success you have at solving those problems. Practice really is the key. And it's a pleasure to help, of course! 🤗😉😃
I swear. I am at "to simplify radical expressions" already and I was given numbers like 180,360 etc and I seriously cant do it. I really loved this video so much Thank you ma'am!!!!!
Thank you very much! I think the next one, with the repeating primes is possibly a bit better. It also has some music I thought was kind of fun for the part where you collect all the primes. I think maybe I had a better handle on the process on the next one. It might be a bit clearer. On this first one I was so excited I'd worked a way of doing it on paper I had to get a vid out immediately. With your 180,360... are you using repeated division using prime divisors? That's a stinky one, by the way; I just did it. Do you know the rule of divisibility for 3? I have a vid on it. Here's the link: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-xdunx3IbkeI.html I got down to 167. It looked fishy so I googled it: it's prime. Like I said, that's stinky. If you didn't already know the rule of divisibility for 3, this is really going to help you on your prime factorization problems. 😉🤗😎💕
How do you know if you have correctly multiplied all of the conceivable combinations of prime numbers together? That part is the only part that is confusing to me.
Hmm. I haven't come up with a 'how to check you've got them all' strategy. Just this, to make sure that you've got everything. Sorry, I don't have an answer to your question at this point except to ask for care and attention as you're going at it. Wish I had a definitive answer for you.
Sorry Grace. It IS a bit fiddly, but if you can stick with it, it does work. If you're doing smaller numbers, you can just go with one of the other methods in the playlist Factors, Prime Factors.
Maybe take a look at the second vid where there are repeating primes. That might help you to see a second example. It IS quite a headache to get your head around. Tbh most of the examples you’ll get I would expect to be 2-digit numbers, and values for which you can immediately find 2 factor pairs. Like 54 is from 6x9. Find the primes of 6 (2 and 3) and the primes of 9 (3x3). Now it’s easy enough to get all your combos I think.
Isn't is crazy that some people charge to teach this But.. the students are saved by these kind of generous u tubers making vids that really hepls us! Thanx❤
Take a look at the second one too, with repeating primes as part of the decomposition. Tbh, I don’t know that we need this very often. I came up with this method in answer to the really horrible times when I’ve seen a class be told to find all the factors using ‘guess and check’. That approach is disheartening for me, never mind seeing kids’ confidence get crushed that way! We want to enable kids as mathematicians, not leave them feeling unable to do it, or even find a way n to start beyond crappy guess n check!
Your videos are really nice 👍 . I found this video when I was in trouble in finding factors of a factors fast 💨, and as a coincidence my hard number was also 210 😊😊🙏🙏😯😯
Let's Do Math It is very much the same idea. But the way its done makes it easier for like the factors ending up like: 2x5x11 where it is 11 to the power of 2
Fabulous! I’m really glad it helps him. I’m not sure if the second video I made on this is simpler to understand; you can be the judge on that. But that one covers a number that features repeating primes, and I think that’s a useful thing to see too. 😃😎💕
Perfect! I’m always happy to help. My videos are sorted into playlists so you can quickly find what you need. There are more playlists than you can see on one screen, so you have to use the arrow to move to the right and see more. 🤗😃😎💕
I’ve NEVER had it explained to me at all! It’s always seemed like some kind of arcane magic that I just couldn’t get. Then when I thought about it through prime numbers, I came up with this way of combining them, and it really works! The second vid, which has repeated primes as part of the prime factorization is maybe a bit easier to understand. Plus it’s got a fun little music break during the phase of pulling out the different factorization. Anyway... I’m really pleased this helps you too! 😉😃🤗😎🤩
Thanks very much! I think they will really find the next one helpful too. That has an example with repeating primes. It’s also in the playlist Factors, Prime Factors. 😃😎🤩
Glad you asked that. There’s a second video showing exactly this scenario. 😃 Have you been on my website? It’s so easy to spot it there. Go to the Resources page (click that link on the signpost), scroll down to the section on prime factorization, and you’ll see it at the end of the list there. 🤗
Thanks very much, I’m glad it helps. If you use my website letsdomath.ca you’ll easily find lots of stuff to help. It’s all set out in topic groups and leads you through each area I’ve covered. There is a second vid I made using this method for finding all the factors, and I think it’s really helpful because it uses repeating primes, and in that vid I use both dividing by a prime to reduce the number, and factor tree. You can do that - mix and match methods for ease and speed. I should say that often, Factorizing questions have smaller numbers, and often you can do them just with your tables knowledge and not need this method. I made these videos because I was upset by something I saw in class one day. As a supporting supply teacher, I observed students given values to factorize that were too big for them and they were told to use ‘guess and check’ to find every factor. Those poor kids struggled and felt so discouraged by the end using this miserable time-wasting ‘strategy’. So I thought up a way to solve anything a teacher might reasonably throw at you. I hate wasting time in math class, there’s a lot to get through and confidence is built by feeling success, not by being discouraged because we haven’t got the tools to solve a problem. Now you have the tools! 😃🤗🥰
That was a 'D'Oh!' moment then. I've had them too, don't worry. Look at it as a practice run. Seriously, I'm very glad this helped you. Every time I do this I can't get over how cool it is! I've seen students be given 'guess and check' and faff about with that for a whole lesson period on just 2 numbers, getting increasingly frustrated as they go along. If they stick with that approach, they will forever think it's some crazy magic thing they can never get. This way, we have a tool to use and we can get to work and get the job done!
@@LetsDoMath By the way, could you please tell me what to do when a number has more than 4 Prime Factors like 2592 which has the prime factors 2*2*2*2*2*3*3*3*3?
For 11+, make sure you are strong in multiplication, and ho through all the fractions stuff you have covered so far. Review and sort out any issues with practice and vids on www.letsdomath.ca I hope you breeze through it with ease and confidence, to a stellar result at the end. 🤩🤗👍😃
Great stuff. Did you see the second vid on this as well? That uses a value that decomposes to repeating primes (2s and 3s). I nailed it on that vid! 😃🤩🤗😎😉
Thank you so much!!! This is exactly what I was looking for...... It's so helpful!! But I'm still confused in calculating big numbers!!! Can you please suggest me how to solve those kind of sums (class 6)
I expect schoolwork not to have students explore huge numbers. By showing you big ones that have been created by combining primes so we can use divisibility rules to spot which primes to divide by, at each stage, I hope I’ve shown that anything teachers give is manageable. But teachers have to give reasonable combinations of primes in the first place. So no including 2 or more that we’re not going to spot like 23 and 17. Only 1 of those with a combo of 2s, 3s, 5s, 7s, 11s and 13. I hope that helps build your confidence. 😃🤗
I wouldn't use this with grade 5. Unless this person's a mega-brain, I'd use something much more accessible, like the one where we list them all line by line. In my playlist Factors, Prime Factors, it's the second method, 'Find all the Factors, Next Step'.
Hi there. Just my personal preference, really. Any time I have an even number I just always start with 2. Of course you could also start with 5. Order doesn't matter as long as you pick all those primes up - just whatever seems easiest is fine.
I actually hated those questions in school - it’s a way to take the whole math period with awful guess-and-check, leaving a person feeling not even close to being good enough. But that’s a load of rubbish, because it’s just that we hadn’t been taught a way to find them all. Once you know this, those questions take their proper place… something you can deal with and move on. Then you can go off to do something more interesting instead. Guess and check is horrible - it means we need a solid strategy and we don’t yet have it. If your teacher tells you to use ‘guess-and-check’, I recommend bugging your teacher for a working strategy that lets you move it. 😉😃🥰
It's really cool to find all factors of any number but what if the prime factorization gives us factors of more than 4 digits how do we will make pairs of factor to get final answer ?? I hope you will answer my comment so I could be clear until exams
Ohh my god broo these Americans learn about prime factorisation in grade 8 😂 but in India they teach us in grade 3 and 4 above that 210 is big number got me 😂
That’s great! Glad to help. You might find the second vid on this very helpful too. That one uses repeating primes: 3x3x3x3 and 2x2 if I remember my values right. It has a fun little bit during the collect all the factors step... Its also in my playlist Factors, Prime Factors. 😃🤗🤩
For 108, you know that’s from 12x9, don’t you? Do you get that right off the bat. It’s even, so you know 2 is a factor. Divide 108 by 2 and get 54. Divide by 2 again and get 27. 2 crops up twice so 4 is a factor. Divide 108 by 4 and get 27 (already found that one, but you can see now you’ve confirmed 4. Think about 3… is it a factor? Well 3 is a factor if 9 and 12… yes it’s a factor. 108 divided by 3 = 36 Thinking in terms of those rainbows we use when we start factoring… 1 x108 on extreme outer edges Then 2x 54 Then 3x36 Then 4x27 2 and 3 are factors, so 6 is too. 108 divided by 6 = 18 Then 6x18 And in the middle spot, 9x12 You do get 12 factors. Did you forget 1x108?
Got bored during quarantine and felt like doing random math , but extremely amplified for fun. Long story short I ended up needed all the factors of this one number that is in the quintillions. I tried my tried and true guess and check method and after not even Making it remotely close to getting all of them that way, I tried using online calculators to cheat and give me the answer. Problem was that the numbers I was using were too much for any of the online calculators to do. I'm hoping this method works at getting them all. 🤓
Well if you ended up creating a number that has hideous primes, it's not going to work, cos you're not going to spot them. If worst comes to worst, you can always go techy on it and use a prime factorization calculator...
Different curriculums based on locations and also how good your school is (government or private) For example private schools in Australia or India can teach this in
Lucky you! It really sucks to be stuck with the lesson where you're told "use guess and check to find all the factors." I hated that so much I came up with this method in fact!
Have you tried the guess and check method?? This is for numbers where you don't have another option except guess and check. To be honest, I'd expect an exam problem of this type to more likely feature a tables value such as 96, which you can break down. 12x8 = 96 so 3 and 4 are factors, 3x8=24 is a factor, 4x8=48 is a factor. You can get 12 from 2x6, so they're factors. Then 2x3=6 and 2x8=16 All I'm doing here is applying the principles from this vid - multiplying all the primes and composites together. That gives us the list: 1, 2, 3, 4, 6, 8, 12, 16, 24, 32,48, 96 Yes I think it's faster, and definitely helpful for an exam because you have a way in. You won't see the question and panic.
