@Lunar0511 Because this is a trick. You need to show that you understand the logic behind the problem. You can't just out an answer and say "full credit" because that doesn't show you learned anything. If you're gonna do it this, way, you need to explain why it works. Ex: Multiplying by 2 and dividing by ten is the same as 1/5 aka dividing by 5
As a math teacher, if a student wrote what she wrote on their paper, I would give full credit. Students wouldn’t even have to put the x2 above the original problem. I told my students there wasn’t ONE right way to do a problem. As long as they didn’t cheat and could explain their thought process, I was okay with it.
@@anonymousperson3023 Except when you do it the whole time, get it right consistently, thus proving you understand the logic behind it... If you didn't, then you wouldn't get it consistently correct. That's the trick.
@@anonymousperson3023 this is bullshit. the point of math isn't to teach you "the logic of math" or whatever you came up with in your head. if that were the case, we wouldn't teach times tables, because times tables is literally using memorization to make problems easier. the point of teaching you math is so that you can DO math in the real world. a trick that makes it easier to DO math and gives you correct answers isn't cheating, it's literally the point of math.
If the division is with 25 - Multiply the number by 4 and put decimals from the last 2 digits If the division is with 125 - Multiply the number by 8 and put decimals from the last 3 places ( I have opted for Vedic Maths in my school) Example - 233 divided by 25 =233 multiplied by 4 (step 1) =932 =9.32 (step2) Hope it helps :)
@@deja_vu_for82 wanna prove it just do: x/125=8x/1000 remove 8 from last fraction by dividing by it on both sides of the last fraction x/125=x/125 x=x x/25=4x/100 remve 4 from last fraction by dividing by it on both sides of the last fraction x/25=x/25 x=x
Someone preparing for competitive exams should be able to figure this thing out on their own It works for division by all numbers whose factors are 2 and 5 only
The process is 5 = 10/2, so rewrite the equation as 7341 / 5 = 7341 x 2 / 10. If instead of learning the "trick" we just taught it like that, then it'd lead to a better understanding of maths.
That wouldnt work for this equation. I dont get the same number simply multiplying by 5 then i do dividing by 2. Much faster to actually just multiply by 5. (Your way would start the number with 35. Actually multiplying by 5 would start the number by 36.). Edit: also there wouldnt be any decimal if you're multiplying. 🤷♂️ what you said is nonsense. (Picturing 7341x5.)
@@CartoonWeasel Multiplying by 5 (or 5/1) is the same as multiplying by 10/2. > Your way would start the number with 35 Do you know how to do division ? 7341x5 = (7341/2)x10 (or the other way around whichever you liked) 3670.5 x 10 (as in moving decimal to the right) multiplying by 10 is easier to do in head than 5, dividing by 2 can reasonably be done in head especailly for even number.
Even easier: x/5 = = 1 * (x/5) ### identity (multiplication) = (1/1) * (x/5) ### equivalent fraction = (2/2) * (x/5) ### equivalent fraction = (x*2)/(5*2) ### distribution (multiplication) = (x*2)/10 ### simplify denominator Regular fractions stuff. You can divide or multiply the numerator and the denominator by the same number and you get an equivalent fraction.
@@proscon4766they just wanted to make sure that the method worked as it would make their life much easier. This method might not be that useful for u, as for me it only takes around 10 seconds to divide it normally, would be faster if i used this method but i would probably forget about it. But it's useful for those that are not that good at math!
In fact, if the digit in the dividend is greater than 4, you should follow another rule I just came up with. When you multiply the digit by 2 and get a two-digit number, like in your case using 6, where 6 * 2 = 12, then you add each digit of the number 1 to the digit to its left. For example: 7346 ÷ 5 You do as shown in the video, and the result is 146812. Here's the rule: you add each digit 1 to the digit to its left. So, the answer will be 14692. Adding the decimal point, the answer is 1469.2. I hope I made the idea clearer.
Do the multiplication normally 7346 x 2. Just like how would you do multiplication as usual. Dont think of this as a magical thing that have no basis or stuff outside of math. This is a shortcut that also use math, so just do it with math normally. The trick can be explained as substituting 5 for 10/2 because 10/2 is equal to 5. Therefor 7346 ÷ 5 = 7346 ÷ (10/2) = 7346 x 2 ÷ 10
so the reason this works is that 5 = 10/2, meaning you can rewrite it like this: 3 ÷ 5 = 3 ÷ 10/2, when we divide fractions, we can flip it and multiply, so 3 ÷ 10/2 = 3 * 2/10 and a fraction is basically division and can be written like this: a/b = a ÷ b, so 3 * 2/10 = 3 * 2 ÷ 10, go left to right, so 3 * 2 ÷ 10 = 6 ÷ 10 and when we divide by 10, we can just move the decimal point 1 place to the left, so 6 ÷ 10 = 0.6, and if you do it fast, it's exactly what's in the video.
I was in second grade i think When i realised if you want to multiply a number by five, you just take that number/2 then multiply with 10. So, 7*5 = 7/2 which is 3,5. Then 3,5*10=35. Also works with bigger numbers. This is like the same thing but reversed.
To prove it just do this: 2x/10=x/5 Since 2*5=10 you can just remove 2 from the numerator and the denominator of the first fraction and then be left with the fraction x/5 Then you will have: x/5=x/5 Remove 5 as it's same on both sides and you have x=x Then you can use the math trick as much as you want as you have proven that it works since dividing by 5, and multiplying by 2 then dividing by 10 gets the same answer. Since it's multiplying you can also do it the other way around dividing by 10 and then multiplying by 2 :-)
@@notyourgirlarsh Have you learnt about multiplication ? 7448 x 2 / 10. Just do the multiplication as usual. Dont think of this as a magical thing that have no basis or stuff outside of math. This is a shortcut that also use math, so just do it with math normally. The trick can be explained as substituting 5 for 10/2 because 10/2 is equal to 5. Therefor 7448 ÷ 5 = 7448 ÷ (10/2) = 7448 x 2 ÷ 10
Because moving the decimal place to the left once is the same as dividing by 10, what she did was multiply the large number by 2/10. Which is simplified to 1/5. She did the same math, just made it look more aesthetically pleasing
@@splashbenine Its simply because 10/2 is equal to 5 . . . She already explain how it works while she calculate it. @RI7 It is a trick because its a roundabout way to do this, but it makes it easier to compute in our head. If you learn about math.
This isn't a random trick, its the equivalent of dividing by 5, which is dividing by 5/1. The reciprocal of that is 1/5, which is equivalent to 2/10. 2/10 is the same as multiplying by 2 •|• 10, so multiplying by 2 then dividing by 10 makes perfect sense :) (for the people who didn't know why this works)
Technically you can do the same thing with multiplying: you just have to split the number in half instead of doubling it, and multiply by ten instead of dividing.
I discovered this one day in fourth grade. Another thing I discovered is that if you want to add up every number up until a certain number, like 1+2+3+4+5 etc. You take the last number you will add and multiply it by half of itself. Then add one half of itself. Example because I think this was confusing: (10 • 5) + 5 = 55 1+2+3+4+5+6+7+8+9+10 = 55 Or x • 1/2 x + 1/2 x
After seeing this I screamed NO F-ING WAY and proceeded to try this on every number I could think of. thank you for this trick it literally made my day
Explanation: Multiplying by 2 then dividing by ten is the same as diving by 5 :)
Exactly. Genius.
Explanations are really helpful for actually learning, much appreciated!
I call witchcraft😂
Exactly, that's what i do!!
That's what she did
Math teacher: THAT'S ILLEGA-
Fr💀
its how mericans do it
@@shartingismypassion Americans? Mexicans? Meow meows? Who?
@@nikolai_simp americans buddy are the population of us
@@nikolai_simpMeow meows
I just divide by 10 and then multiply the quotient by 2. Pretty much what you did but in reverse
yea this is better imo
yeah i did this alot when i was younger and was referred to as smart
I still do that 😊
Same, it’s easier for me to just double it after
That's the same thing, you just moved the decimal point before instead of after. Sob.
and then the teacher goes "You are wrong because you did not put the solution"
my math teacher would be like “it’s wrong because you didn’t do it my way” when we got the same answer
@Lunar0511 Because this is a trick. You need to show that you understand the logic behind the problem. You can't just out an answer and say "full credit" because that doesn't show you learned anything. If you're gonna do it this, way, you need to explain why it works. Ex: Multiplying by 2 and dividing by ten is the same as 1/5 aka dividing by 5
As a math teacher, if a student wrote what she wrote on their paper, I would give full credit. Students wouldn’t even have to put the x2 above the original problem. I told my students there wasn’t ONE right way to do a problem. As long as they didn’t cheat and could explain their thought process, I was okay with it.
@@anonymousperson3023 Except when you do it the whole time, get it right consistently, thus proving you understand the logic behind it... If you didn't, then you wouldn't get it consistently correct. That's the trick.
@@anonymousperson3023 this is bullshit. the point of math isn't to teach you "the logic of math" or whatever you came up with in your head. if that were the case, we wouldn't teach times tables, because times tables is literally using memorization to make problems easier. the point of teaching you math is so that you can DO math in the real world. a trick that makes it easier to DO math and gives you correct answers isn't cheating, it's literally the point of math.
If the division is with 25 - Multiply the number by 4 and put decimals from the last 2 digits
If the division is with 125 - Multiply the number by 8 and put decimals from the last 3 places
( I have opted for Vedic Maths in my school)
Example - 233 divided by 25
=233 multiplied by 4 (step 1)
=932
=9.32 (step2)
Hope it helps :)
Thank u soo much❤
@@deja_vu_for82 wanna prove it just do:
x/125=8x/1000
remove 8 from last fraction by dividing by it on both sides of the last fraction
x/125=x/125
x=x
x/25=4x/100
remve 4 from last fraction by dividing by it on both sides of the last fraction
x/25=x/25
x=x
This trick literally saved my time in my competitive exam thanks a lot😊😊
What competitive exam has dividing by one digit numbers
@@trafalgarq805Could be problem solving that has a step in wich you have to divide by 5
Someone preparing for competitive exams should be able to figure this thing out on their own
It works for division by all numbers whose factors are 2 and 5 only
You people in the reply section are not at all helpful
bruhhh i am not trolling i was appreciating
@@splashbenine
Indian maths teacher- you have to show the process
The process is 5 = 10/2, so rewrite the equation as 7341 / 5 = 7341 x 2 / 10. If instead of learning the "trick" we just taught it like that, then it'd lead to a better understanding of maths.
Not in jee kid
Explanation: 7341 / 5 = 7341 / 10/2 then flip the factor to make it a multiplication: 7341 * 2 / 10 = 14682/10 = 1468.2
I thought that only I figured out it for the first time 😂😂😂
Yeah this is a trick I've used ever since first learning the time table and division, I thought everyone did this but I guess not?
It’s the same thing for multiplying by 5! You just divide the number by two and move the decimal point to the right once
no shit
nahhh for multiplying by 5! you multiply it by 12 and then add a 0 in the end
5! ≠ 5
That wouldnt work for this equation. I dont get the same number simply multiplying by 5 then i do dividing by 2.
Much faster to actually just multiply by 5.
(Your way would start the number with 35. Actually multiplying by 5 would start the number by 36.).
Edit: also there wouldnt be any decimal if you're multiplying. 🤷♂️ what you said is nonsense. (Picturing 7341x5.)
@@CartoonWeasel Multiplying by 5 (or 5/1) is the same as multiplying by 10/2.
> Your way would start the number with 35
Do you know how to do division ?
7341x5 = (7341/2)x10
(or the other way around whichever you liked)
3670.5 x 10
(as in moving decimal to the right)
multiplying by 10 is easier to do in head than 5, dividing by 2 can reasonably be done in head especailly for even number.
This is just simple math. Because 5 can be written as 10/2 so 7341÷5 becomes 7341*2÷10 giving 1468.2
this helps for me though! i never knew this
Even easier:
x/5 =
= 1 * (x/5) ### identity (multiplication)
= (1/1) * (x/5) ### equivalent fraction
= (2/2) * (x/5) ### equivalent fraction
= (x*2)/(5*2) ### distribution (multiplication)
= (x*2)/10 ### simplify denominator
Regular fractions stuff. You can divide or multiply the numerator and the denominator by the same number and you get an equivalent fraction.
@@technolus5742 bro proved that x/5 = 2x/10 is true
@@trafalgarq805 😂
What is ×/5?
I am in 5th grade@@trafalgarq805
People who went to check
in the calculator🤣🤣
👇
Beggar for likes. No.
@@CombineCubingwhy do people care so much- 😭😭😭 no one will tell me why bro
Who tf checks this??? Nvm I forgot this is for toddlers
@@proscon4766they just wanted to make sure that the method worked as it would make their life much easier. This method might not be that useful for u, as for me it only takes around 10 seconds to divide it normally, would be faster if i used this method but i would probably forget about it. But it's useful for those that are not that good at math!
@@mission_apollo because these kinda comments are useless and just want likes
I was so proud when I figured this out in third grade.
Me too haha 😂
Wow took me like at least 7th grade 😭
I found out in 4th grade
Please, what do you do if the last number (or any number) was more than 4? As in 7346 ÷ 5.
Would you add to the number left of the decimal point?
In fact, if the digit in the dividend is greater than 4, you should follow another rule I just came up with. When you multiply the digit by 2 and get a two-digit number, like in your case using 6, where 6 * 2 = 12, then you add each digit of the number 1 to the digit to its left. For example:
7346 ÷ 5
You do as shown in the video, and the result is 146812.
Here's the rule: you add each digit 1 to the digit to its left. So, the answer will be 14692.
Adding the decimal point, the answer is 1469.2.
I hope I made the idea clearer.
You can also just double it using column multiplication...
@@hyq2004 You dont need another rule, just do the multiplication normally.
7346 ÷ 5 = 7346 ÷ (10/2) = 7346 x 2 ÷ 10
Do the multiplication normally
7346 x 2. Just like how would you do multiplication as usual.
Dont think of this as a magical thing that have no basis or stuff outside of math. This is a shortcut that also use math, so just do it with math normally.
The trick can be explained as substituting 5 for 10/2 because 10/2 is equal to 5. Therefor
7346 ÷ 5 = 7346 ÷ (10/2) = 7346 x 2 ÷ 10
I am genuinely amazed there are people who DON'T do this. To me it's like "duh? Of course that's what you should do".
Man where was this channel when I was in school 😂💔
W8 thats actually so good..
Not like i will use it tho😅
so the reason this works is that 5 = 10/2, meaning you can rewrite it like this: 3 ÷ 5 = 3 ÷ 10/2, when we divide fractions, we can flip it and multiply, so 3 ÷ 10/2 = 3 * 2/10 and a fraction is basically division and can be written like this: a/b = a ÷ b, so 3 * 2/10 = 3 * 2 ÷ 10, go left to right, so 3 * 2 ÷ 10 = 6 ÷ 10 and when we divide by 10, we can just move the decimal point 1 place to the left, so 6 ÷ 10 = 0.6, and if you do it fast, it's exactly what's in the video.
Explained better.👌🏻
my math teacher: 'WORKING OUT?!?!'
Makes perfect sense. What a neat way to think about it.
Damn thats useful
I was in second grade i think When i realised if you want to multiply a number by five, you just take that number/2 then multiply with 10. So, 7*5 = 7/2 which is 3,5. Then 3,5*10=35. Also works with bigger numbers. This is like the same thing but reversed.
To prove it just do this:
2x/10=x/5
Since 2*5=10 you can just remove 2 from the numerator and the denominator of the first fraction and then be left with the fraction x/5
Then you will have: x/5=x/5
Remove 5 as it's same on both sides and you have
x=x
Then you can use the math trick as much as you want as you have proven that it works since dividing by 5, and multiplying by 2 then dividing by 10 gets the same answer. Since it's multiplying you can also do it the other way around dividing by 10 and then multiplying by 2 :-)
thank you for the 2x/10 = x/5, i FINALLY got it!
the fact that this trick is needed to be shared explains how most people are lazy and somehow not lazy enough to do 2 more procedures
more like uninterested and closed minded
Ive been doing this for so long, im so glad someone's talking about this,
Thanks for that!
How can we apply it in 7448?
1489.6
Why didn’t you tell us?
@@Dream.big.dreams I already thought people already knew about it, I literally saw this method when I was 12.
@@notyourgirlarsh Have you learnt about multiplication ?
7448 x 2 / 10. Just do the multiplication as usual.
Dont think of this as a magical thing that have no basis or stuff outside of math. This is a shortcut that also use math, so just do it with math normally.
The trick can be explained as
substituting 5 for 10/2 because 10/2 is equal to 5. Therefor
7448 ÷ 5 = 7448 ÷ (10/2) = 7448 x 2 ÷ 10
....then I became a math genius...
Read the book vedic math you will be calculator 😅
My brain calculated before you multipled 😭
Just devise it by 10 (move the decimal 1 degit to the left) and multiply by 2
when bro understands that 2*1/10 = 1/5
Brooo! This was way too easy.. We need more teachers like you, ma'am! 🥺💗
Because moving the decimal place to the left once is the same as dividing by 10, what she did was multiply the large number by 2/10.
Which is simplified to 1/5.
She did the same math, just made it look more aesthetically pleasing
Me doing my math exam in the morning checking my for you page and sees this
Maths way of saying "double it and give it to another person"
WE NEED MORE PEOPLE LIKE HER!!!
No we don't.we need people who actually tell us how stuff works and not simply list it as TriCkS* this is some basic shit why rote learn it as "TRICK"
@@anketmohadikar8767She should've explained why this works instead of just showing something and calling it a "trick"
@@splashbenine Its simply because 10/2 is equal to 5 . . .
She already explain how it works while she calculate it.
@RI7 It is a trick because its a roundabout way to do this, but it makes it easier to compute in our head. If you learn about math.
@@user-oz6jx1kt6t she never explained why it works or how it works, she just showed it "works"
I wish I knew this trick before my math exam 😢☠️
That's just dirty. Keep em coming
All you need is a calculator😂
well we need it for non-calculator exam
Just cheat
@@JakeTheBrainDamagedOne well i rather not
Okay you do you
@@user-pj8us1ed1qquestions like this does not come in the exam without being able to use a calculator plus. These questions will never to high grades
Did it faster than you in my head bruh.
☠️ she already know the answer before u even watch the video
Double-double method. Gotta love it
This isn't a random trick, its the equivalent of dividing by 5, which is dividing by 5/1. The reciprocal of that is 1/5, which is equivalent to 2/10. 2/10 is the same as multiplying by 2 •|• 10, so multiplying by 2 then dividing by 10 makes perfect sense :) (for the people who didn't know why this works)
imma forget this and end up doing long division every time
Short division is way easier, you dont need long division outside of polynomial division
Maths teacher be like "WHERE IS THE SOLVING PARTTTT????"😂
I’ll just stick to my long division 😂
This is pretty useful for figuring out a 20% tip. That's how I've always done it
BRO! TODAY WAS MY FREAKING MATH EXAM AND THIS WOULDA HELP ME IN DMAS FRACTION SM
Can't believe Western people struggle with these
Sticking a pink pencil behind your ear helps to make you a whizz at maths.😂
Fantastic trick 👌 👏
I just normally divide why over complicate it.
I add a zero at the end and then half it.. idk that always felt easier for me
Calclator has entered the chat…
always used this trick when i was around 10 years old but never saw someone else use it, nice
For dividing with 25 just the same but the no. gets multiplied 4 times and move the decimal pts 2 places on the left
Its so crazy that, that works
this is cool but it's important to know what to do when you're carrying a large number in the middle AND how to deal with zeroes in the number.
Ok literally I’ve been thinking of this concept for so long and I’ve used it in math. I’m so glad someone else is talking about it. 😊
Holy crap. Why where you not my teacher in the 80's. While I was in elementary school. I remember learning all this long hand. Mind blowing.
All I need is my calculator!! While you were explaining, I had the answer within seconds and had to wait for you ! 😂😂😂😂
Technically you can do the same thing with multiplying: you just have to split the number in half instead of doubling it, and multiply by ten instead of dividing.
Calculator crying for justice in the corner .......
This is what bro was talking bout when he said "the math teacher kinda bad"
I discovered this one day in fourth grade. Another thing I discovered is that if you want to add up every number up until a certain number, like 1+2+3+4+5 etc. You take the last number you will add and multiply it by half of itself. Then add one half of itself. Example because I think this was confusing:
(10 • 5) + 5 = 55
1+2+3+4+5+6+7+8+9+10 = 55
Or
x • 1/2 x + 1/2 x
NO
Actually it is 10 * 11 = 110 / 2 = 55
I guess that could work too
Interesting.... if that's a thing, there should be a general proof for all natural numbers.
@@eugenkeller My way is how it is taught in Middle School
I was thinking this looks like a long way to get to the answer and then suddenly it was the answer
How have i never seen this clear solution staring me right in the face
I have literally never seen anyone writing the dividing symbol actually like that
While this is a neat trick, what is really important is understanding why it works.
Multiplying by 5 can be done with the reverse and is really helpful!
As feedback, you should discuss what happens when you need a carry. Otherwise, nice video!
That’s wild, i’m using this always
I never watched the video before and knew exactly what you were gonna do.
If you’re not sure how much to leave for a tip first double the number, then move a decimal point over by 1.
the last time i told my class this most of them were like "why do two steps when you just do one step which is just divide by 5"
Sounds like they don't know how to do long division. Or maybe they're better at it than just multiplying and moving a decimal point.
Instructions unclear, i found a perfect odd number
Crazy Matrix! Dodge bullets in slow mo, with pinkpencilmath !
That's genius! Why didn't I ever know about this?! Thank you❤
I came up with adding a zero and dividing by 2 in order to multiply anything by 5. It makes sense that it works the other way around.
This is how I’ve calculated tips my entire adult life
Me watching this one night before my final exam of maths 😶
Oh my god, i figured out this trick in elementary school and thought it was so cool, I’ve never heard anyone else mention it
I mean anyone can solve it under 30sec if they can do basic math nicely. But it's a good trick for people who are a bit ad at math 👍
Eminem been real quiet since this dropped
This is actually a really good trick
Math teacher : THAT AINT ALLOWED, THATS ILLEGA-
Me watching this while procrastinating on my math homework
-WAIT, WAIT JUST ONE MINUTE
Need water? Just melt ice.
Math teachers be like: "YOU CAN'T DO THA-
Crazy maths tricks that everybody already knew.
What's next? water is wet !! ?
Diving a number by 5 or 2 is my fav sort of division.
After seeing this I screamed NO F-ING WAY and proceeded to try this on every number I could think of. thank you for this trick it literally made my day
I always think like that when multiplying with 5, idk why I haven’t thought the same way with divisions
I did this all the time!
I'm glad you teach this trick for everyone
You can do the inverse when multiplying by 5. Just divide by 2 and move the decimal point.
Thank you the trick. ❤❤❤
That's a cool way to see a fraction principle in a fun rule (i'm a math teacher)
I thought of this by myself and thought I invented something new till I realized I wasn’t the only one how knew
I think a better trick is knowing how to convert dividing into multiplying and dividing
Expl. /5 = *2 /10 OR. /25 = *4 /100
I was expecting some "common core" garbage but I was pleasantly surprised. Thanks!
I do the same thing when leaving a good 20% tip. Just double it and move the decimal point.
*Smirks at it in Indian*
I just woke up from a sleepy sleep 😂