Percentage Trick - Solve precentages mentally - percentages made easy with the cool math trick!

Percentages can be done mentally both accurately and rapidly using this cool math trick. Become a genius in no time!

---

Closed Caption:

hello and welcome to the techniques
channel but we're gonna be having a look
at this video is we're going to be
having a look at why of working at
percentages in your head it's going to
start out in this video we're just gonna
be looking at a fairly simple
percentages say ones that have fives and
tens and fifty percent of a number or or
twenty-five percent of a number of fifty
percent or seventy five ninety-five
percent like I just wanted a fairly
simple
they're going to walk it in a lighter
video get on to the more complex
versions but this is a really really
great little introduction for so first
off it's good to be able to understand
what percentage means our percentage
percentage is literally if you see a
percent has two parts the word here by
the way this permits out of sent means a
hundred a percentage number is just a
number out of a hundred
so what was that much further ado we'll
see he you can go on this particular
thing
yeah ok so first off and ego about that
how fast could you work at a 15 set of
ID
then hopefully you've already got the
answer hopefully you got the answer of
12
yeah okay i know that's a hella weight
is it really quickly if this works on
the idea of just a couple of things and
I'm gonna drop these the idea that stuff
we are going to introduce the idea of a
hundred percent of a number fifty
percent of a number ten percent of a
number and 5 percent of a number now
we're going to be using this a lot in
this video today
a hundred percent of a number is the
actual number itself so an example of a
hundred percent of ID would be ID like a
hundred percent of 70 70 hundred percent
of 720 is 720 fifty percent of a number
half of the number is half of a hundred
ok
is this it is percent disease and of a
hundred against a hundred ever hundreds
of full man this is fifty and a hundred
half the number
so half of ID fifty percent of ids forty
fifty percent of 12 is six fifty percent
of 32 is 16 half the number
now we can look at ten percent of a
number which is 10 part of a hundred
really really easy because it's the same
as dividing by 10
yeah for example over at three numbers
sitting here so i'm going to use it as
my example 12 will get ten percent of 15
it's a matter of just moving the decimal
places of decimal places usually here
and I would move it back left so it
become here
so the end you ten percent of our 15
would be 1.5 ten percent of ID the
decimal places here and would move it
back one to the left to ten percent of
ID is I ten percent of 12
we move it back and it becomes one . two
types of the United an idea
ok so ten percent we just divide this
number by ten
so ten percent of ID site five percent
of a number is just half of ten percent
so in five percent here before I k
yeah we're just going to use this idea
in this video tonight so remember those
these are what you need to know for
working at these numbers
ok so fifteen percent is made up of two
things . up in the ten percent portion
and far too said portion right you will
be able to start doing these in your
head by the way and I count you as we go
along to try and work them and you want
to wear them at your head
try to wear them on a piece of paper and
then see if we can get the same answer
as I do so
ten percent of ID is I'd five percent of
that is half of this so it's four then
what we do is we just add these together
because 10 plus 5 is 15
we're just adding these guys together I
plus 4 is 12
I can't go through another example
ok what about we go through i'm going to
just a nice one for the minute what
about we do this one sixty percent of 42
yeah what you might notice that pause
and try to go to go
you might try to work at what is right
up my alley off now the easiest way I
getting there is a 50-percent number if
you remember that's half and I ten
percent number
okay and then you're going to add these
together side
fifty percent is half which is 21 ten
percent is your moving this decimal
place you get really good doing this is
4.2 and you're adding these together
ok going to save on the unit up there
you doing here - 21 and 4.2 is 25.2 or
I'll go another one here this is a bit
of a highly i'm going to use that idea
of a hundred percent number here i'll
give you a bit of a hat heads up on this
one on a work at ninety-five percent so
you might be taking something away of
720
ok so what a guy
ok so the idea is we're going to have a
hundred percent usually wouldn't need to
really think about this is just a number
here which is 720 and we're going to
take a while I five percent so we have
720 @ m % would be-- movie here
the decimal place to become 72 and half
of that would be 36
we're not adding this on by the way
because it's 95 this is a hundred title
by five so we actually going to take
this or why
so I 720 x and y 36
hopefully it really really fast these is
694
I didn't have other videos we look at
how to rapidly subtracting and rapidly
multiply things
okay so how'd you go with these i cannot
again i'm going to put a couple more up
just to give you a bit of practice i'll
tell you what i'll do i'll put three out
right now and then what you could do is
you could pause the video trying to work
through the trying to work through the
mentally trying to work through them on
a piece of paper and then we'll go
through the answers like a chicken
so working that mentally check your
answers on a piece of paper and then
we'll go through them
so what about the first one will be
fifty five percent of 360
the next one is going to be a bit of an
easy one twenty-five percent of 860 give
you a little hint with this 24 opposite
you can also think it was a quarter of a
bit of a hit
I'm going to work it out both wise and
we're going to do ID five percent are
620 all right pause the video give me a
guy
all right - you pause the video and
hopefully where you've given him again
and hopefully you got some pretty good
answers is so
fifty-five percent is my numbers as you
want realize a fifty percent which is
half
ok a hundred ninety plus ten percent a
half of that but you might also realize
that it's fifty percent you can actually
just move this decimal place and get
writing
ok because fifty percent and five
percent is that's just one tenth of that
okay so get this answer of a hundred
ninety i get twenty-five percent of 560
yeah you could easily work this one out
no more than a few people will start why
they get a look at that inside
twenty-five percent since the same as
dividing by 4 is it
twenty-five cents a quarter of a number
same I just divide this number by four
and if you did that you would get the
answer i divided by 4 is 26 / 4 is one
that you carry it across and you get 250
all right , also working out using this
particular method i can because this is
all just a bit of practice as well so 25
set you might realize the spine up
through ten percents and a five percent
so it's going to be
I d6 and ID seeks and have i.d six which
is 43 so it would add all these together
I d 6 plus ID seeks is going to be a
hundred and seventy to a hundred and
seventy two plus in there 43 is 215 ok
so i'll write that in 86
+ ID seeks which is a hundred and
seventy 372 sorry
+ 43 which gives us his answer here is a
2 15 there answer
now what about eighty-five percent of
620
I think the easiest way to do this one
is looking at a hundred percent number
and then getting rid of a ten percent
and also a five percent this does my
side no no we had does occasionally get
a bit tricky and had some of these not
be looking to me to hear that that's ok
so we're going to start with
620 and we're going to take away ten
percent which is going to be 62
so all right this working at that was
thinking as we go
620 take away 62 and then we're gonna
take away half of this which is 31 all
that we want think 60 - 1:31 it's 93 so
620 like why not only three is 527
yeah these will require a bit of
practice and I'll be the first to admit
to some numbers they're going to be
harder than others like at some of these
numbers are definitely much harder than
others
obviously it's a lot easier to work at
fifteen percent of a number and it is to
work at eighty-five percent of a number
just based on this map is this idea okay
anyway do practices you will get better
and this is what it's all about trying
to get better at working things mentally
the next video we're going to lead to
right now so let's start looking at say
we're working at not just with the fives
and tens and that's what to do we start
looking at things are twenty-two percent
or fifty three percent or eighty-seven
percent so where we get away from these
invisible numbers by five
you know thanks for watching see you
next time