Singapore Math: Grade 3a; Unit 1 (part 5) Video Lecture | Mathematics Lesson for Grade 3 (Singapore) - Personal Learning

let's keep doing problems to see if we
can understand place value even better
so let me write down a number then I'll
ask you a question about it the numbers
well I'll just write it down I don't
even want to read it out to you so
that's the number so I'll tell you a
couple of things well you know what what
is this to stand for right here well
what places it in this is the ones place
tens place hundreds place thousands
place right so it's two in the tens
place so what's two in the tens place
that's two times ten so this this digit
the digit is two so it represents the
value 20 right and I'll give you even
another one what does the six represent
the digit sinks
well what places it in this is ones tens
hundreds thousands right and I don't
notice I've stopped doing all the color
coding because I think we're beyond that
now so this isn't a thousands so the
digit is six and it's essentially saying
we have six thousands so it's value that
it represents is six thousand so maybe
you want to pause the video try it
yourself I want you to figure out what
value just is to represented twenty and
six represent six thousand what value
does eight and four represent you may
want to pause the video because I'm
about to move forward well maybe you've
unpause now so let me tell you the
answer well that for that's in the ones
place right so the digit is 4 but it
also just represents four ones so it
actually just represents four right
that's its value it's digit is 4 and it
represents 4 times 1 or 4 the 8th that's
in the hundreds place right so it
represents eight times a hundred and so
what what value does it represent it
represents 800 and if I color-coded this
would have been in green this would have
been brown this would have been what
color did I use for the tens place Oh
purple and this would have been yellow
but I think I think we're beyond that
now but we see that six thousand eight
hundred twenty four is the same thing as
six thousand plus eight hundred plus
twenty plus four
let me ask you another question let me
let me write down a bunch of numbers so
let's say that I'm gonna write a bunch
of numbers and what I want you to do
well let me write the numbers first so
the first number is the second number is
and the third number is and what I'm
asking you is what is the value what
value does the digit 5 stand for in each
of these numbers the digit five so maybe
you want to pause the video try it
yourself because I'm about to give you
the answer so once again you just have
to say well well sir called let me let
me do the first one so what this is the
ones place tens place hundreds place so
our 5 is in the hundreds place so this
means 5 times 100 or 500 can of a
hundred so this equals 500 so in this
this example it's 3521 so the five
represents 500 what about this case well
this is the ones tens hundreds thousands
place so the five is in the thousands
place so what does it represent it
represents five times 1000 or you can
even say a thousand plus one thousand
five times you could say you know it
could be five circles of a thousand it
could be this one two three four five
each of those 1000 if each of those are
thousand what does that represent what's
five times a thousand or five thousand
that's the value of the five there right
this is five thousand plus two hundred
plus ten plus three or five thousand two
hundred and thirteen and similarly this
is the ones place this is what the tens
place so this tells us the number of
tens so we essentially have five tens
one two
three four five let's assume that they
were all the same size so each of these
are tens and once again how do I know
those were tens because this is the tens
place tens place
that's the tens place and if we five
tens that's five times ten so that's 50
so the value of the five in that
situation is fifty let's do another one
similar I'm doing it in bunch of
different directions and I've I've
gotten these from the Singapore math
workbook which you should get and you
could you know do my head of time or do
them after I I cover them whatever is
useful for you so now I'm actually gonna
write out the places let me let me write
a number really huge now I'm actually
I'm just doing one color though let's
say this is my number and what I'm going
to actually label the places this time
so what what place is this we could
start on the right or the left so start
at the right cuz we'll start at the
smallest place this is the ones what
place is this this is the this should be
second nature to you now that's the tens
this is the hundreds hundreds and this
is the thousands so what in in this
number I want you to go through each
place tell me what the digit is and then
tell me what value it represents maybe
you want to pause it so here the digit
the digit is eight we do it in yellow
the digit is eight eight is the digit
and what value does it represent how
many marbles if you take our original
example what's in the ones place so it
represents eight times one so its value
is also eight value is also eight it
represents eight now we have six in the
tens place how do we think about that
well now the digit is clearly six right
we can just see it right there let me do
it in two so the digit
is six but what does it represent it
represents six tens so if each of these
circles were ten so one two three four
five six so each of these are ten it
represents so it's 10 20 30 40 50 60 so
it represents 60 so 60 is the value
that's what it represents if we go to
the form the digit is 4 right that's
just the numeral the thus this you know
this this number that's that's the digit
the digit is 4 but what value does it
represent well it's in the hundreds
place right so it represents 4
hundredths so it represents so its
values four hundred four hundred and I
could have drawn out four cans of 100
and I think you'll you'll get the point
now and similarly the digit here clearly
is three when I say data I'd say what's
the numeral what's the symbol we're
using the digit is 3 and what's the
value what's in the thousands place so
it represents three thousand value is
three thousand and so this number is
three thousand plus four hundred plus 60
plus eight and if we want to say it it's
three thousand four hundred and
sixty-eight
let's do one more example like that
let's say I have this number
what's the value of each of these digits
let me label it and you might want to do
these for yourself this is the ones
place this is the tens place
this is the hundreds I'll just write hun
this is the thousands place right so
what's the value of the digits seven
well it's in the ones place so it
represents seven times one so it's value
is just seven what's the value what
value does this three represent it's in
the tens place so it represents three
tens so it's value is thirty right three
tens three cans of ten would get you 30
or three times 10 is 30 then if we have
a 1 in the hundreds place by the same
logic if we have 100 this reference the
value this of this digit is a hundred
and the value of this 8 and the
thousands place
well that's eight thousand right I could
draw so the digit tells you how many
thousands are I could draw eight cans
that each represent a thousand so we
have eight thousand
so let's we've been do it we've done a
lot and maybe you're getting bored of
you know just one number after another
and we're trying to know what's the
digit what's the value let's let's start
comparing a few numbers what if I were
to ask you what's larger or what's
greater this number or this number so
how do we think about this well let's
draw it in terms of cans right so what
how many ones do we have here we have
six ones here so that's 100 UPS I
thought I was using the circle tool
that's one two three four five six how
many tens do we have we'll just have one
10 I'm using on the same colors that
I've used the whole time and then how
many hundreds do we have we have three
of them you can imagine each of these
circle that's a can of 100 with three
hundreds and so if I were to write them
in that's a hundred that's a hundred
that's a hundred
that's ten and then each of these are
one let's do the same thing here let's
start with the hundreds how many
hundreds do we have this ones place tens
place hundreds place so we have two
hundreds that digit two in the hundreds
place tells us how many canisters of a
hundred marbles maybe we have so that's
one hundred and that's a hundred and
that that says we have six canisters of
ten marbles have to draw us six
canisters one two three four five six
six each of those have ten ten ten ten
ten ten ten and then we have four
individual marbles right so that's one
whoops one two three four and the each
of these represent one because they're
in the ones place so if we're comparing
the two numbers you know you might want
to start in the one small you can say
well six we have more six individual
marbles compared to before you might be
tempted look in the tens place where you
say wow they're more tens here than here
but what you have to realize is even one
canister of a hundred is more than all
of this combined so you really want to
count the largest canisters right
because if we it because the more you
add you would add another canister like
if you think of it this way all of these
combined all of these combined still
don't make a canister of 100 if they did
we would have put another canister of
100 here right so actually this canister
of 100 right here is bigger than all of
this combined so this number 316 is
bigger than 264 so a general rule if
you're looking at two numbers and you
want to figure out which is biggest or
which is the largest number or which is
greater you want to look at the largest
place value so in these two numbers
we're looking at the hundreds place so
this in this place we have 300 in here
this situation we only have 200 and the
rest of it really does
matter because all of this sixty-four
combined still doesn't add up to this
hundred and we have this hundred and we
have another sixteen so just you know
simplify just look at the largest place
value the one to the the furthest one to
the left and that will tell you which
number is larger so let's do one more
actually
now this video is getting a little long
I will continue in the next video see
you soon