NCERT Textbook - Birds Come, Birds Go - Notes | Study Mathematics for Class 2: NCERT - Class 2

 Page 1


2019-20
Page 2


2019-20
Uhm---m!
One       card for
this whole group!
10
Thiscouldbeagoodchancetoinitiateadiscussionaboutmigratingbirdscomingfromfar-off
places. Alsoencourageandhelpchildrentorecognisepatternsinwhichdifferentbirdsfly.
Let us count
them using
our cards.
And six      cards
for this group
of birds.
1
But where
did they all
come from?
So, these cards
show 16 birds.
10
1
1
1 1
1 1
112
Inchapter8,childrenwouldhavemadetokencards.Thesametokencardsshouldbeused
beforechildrendowrittensums.
Putting all the      s
together, we get
eleven      s. Of
those, ten      s
make one .
And we are left
with one .
Now putting together
all the       s, we get
four       s.
113
2019-20
Page 3


2019-20
Uhm---m!
One       card for
this whole group!
10
Thiscouldbeagoodchancetoinitiateadiscussionaboutmigratingbirdscomingfromfar-off
places. Alsoencourageandhelpchildrentorecognisepatternsinwhichdifferentbirdsfly.
Let us count
them using
our cards.
And six      cards
for this group
of birds.
1
But where
did they all
come from?
So, these cards
show 16 birds.
10
1
1
1 1
1 1
112
Inchapter8,childrenwouldhavemadetokencards.Thesametokencardsshouldbeused
beforechildrendowrittensums.
Putting all the      s
together, we get
eleven      s. Of
those, ten      s
make one .
And we are left
with one .
Now putting together
all the       s, we get
four       s.
113
2019-20
Uhm---m!
One       card for
this whole group!
Thiscouldbeagoodchancetoinitiateadiscussionaboutmigratingbirdscomingfromfar-off
places. Alsoencourageandhelpchildrentorecognisepatternsinwhichdifferentbirdsfly.
Let us count
them using
our cards.
And six      cards
for this group
of birds.
But where
did they all
come from?
So, these cards
show 16 birds.
112
So, the total number of birds is 41.
Inchapter8,childrenwouldhavemadetokencards.Thesametokencardsshouldbeused
beforechildrendowrittensums.
D Soon 25 more birds flew in. Let us add to see how many
birds in all there are now.
For 16 + 25 we write:
+
10
1
10 10 1 1 1 1 1
10
1 1 1
1 1 1
1 6
2 5
+
10
1
10 10 1 1 1 1 1
10
1 1 1
1 1 1
10
1 6
2 5
1
1
+
10
1
10 10 1
10 10
1 6
2 5
4 1
1
Putting all the      s
together, we get
eleven      s. Of
those, ten      s
make one .
And we are left
with one .
1
10
1
1
1
Now putting together
all the       s, we get
four       s.
10
10
113
2019-20
Page 4


2019-20
Uhm---m!
One       card for
this whole group!
10
Thiscouldbeagoodchancetoinitiateadiscussionaboutmigratingbirdscomingfromfar-off
places. Alsoencourageandhelpchildrentorecognisepatternsinwhichdifferentbirdsfly.
Let us count
them using
our cards.
And six      cards
for this group
of birds.
1
But where
did they all
come from?
So, these cards
show 16 birds.
10
1
1
1 1
1 1
112
Inchapter8,childrenwouldhavemadetokencards.Thesametokencardsshouldbeused
beforechildrendowrittensums.
Putting all the      s
together, we get
eleven      s. Of
those, ten      s
make one .
And we are left
with one .
Now putting together
all the       s, we get
four       s.
113
2019-20
Uhm---m!
One       card for
this whole group!
Thiscouldbeagoodchancetoinitiateadiscussionaboutmigratingbirdscomingfromfar-off
places. Alsoencourageandhelpchildrentorecognisepatternsinwhichdifferentbirdsfly.
Let us count
them using
our cards.
And six      cards
for this group
of birds.
But where
did they all
come from?
So, these cards
show 16 birds.
112
So, the total number of birds is 41.
Inchapter8,childrenwouldhavemadetokencards.Thesametokencardsshouldbeused
beforechildrendowrittensums.
D Soon 25 more birds flew in. Let us add to see how many
birds in all there are now.
For 16 + 25 we write:
+
10
1
10 10 1 1 1 1 1
10
1 1 1
1 1 1
1 6
2 5
+
10
1
10 10 1 1 1 1 1
10
1 1 1
1 1 1
10
1 6
2 5
1
1
+
10
1
10 10 1
10 10
1 6
2 5
4 1
1
Putting all the      s
together, we get
eleven      s. Of
those, ten      s
make one .
And we are left
with one .
1
10
1
1
1
Now putting together
all the       s, we get
four       s.
10
10
113
2019-20
114
In the same way, we will add the number of swans
and cranes.
Also try adding
without writing.
The total number of swans and cranes is ___________.
Number of Swans
Number of Cranes
+
10
1
3 9
3 1
10 10 10 1
1 1 1 1 1
1 1 1 1
10 10 10
Suraj, don't be sad!
Let us hope they
come back next year.
115
There are
31 cranes and
39 swans.
Let us find out
how many swans
and cranes
there are in all.
How Many Cranes and Swans?
2019-20
Page 5


2019-20
Uhm---m!
One       card for
this whole group!
10
Thiscouldbeagoodchancetoinitiateadiscussionaboutmigratingbirdscomingfromfar-off
places. Alsoencourageandhelpchildrentorecognisepatternsinwhichdifferentbirdsfly.
Let us count
them using
our cards.
And six      cards
for this group
of birds.
1
But where
did they all
come from?
So, these cards
show 16 birds.
10
1
1
1 1
1 1
112
Inchapter8,childrenwouldhavemadetokencards.Thesametokencardsshouldbeused
beforechildrendowrittensums.
Putting all the      s
together, we get
eleven      s. Of
those, ten      s
make one .
And we are left
with one .
Now putting together
all the       s, we get
four       s.
113
2019-20
Uhm---m!
One       card for
this whole group!
Thiscouldbeagoodchancetoinitiateadiscussionaboutmigratingbirdscomingfromfar-off
places. Alsoencourageandhelpchildrentorecognisepatternsinwhichdifferentbirdsfly.
Let us count
them using
our cards.
And six      cards
for this group
of birds.
But where
did they all
come from?
So, these cards
show 16 birds.
112
So, the total number of birds is 41.
Inchapter8,childrenwouldhavemadetokencards.Thesametokencardsshouldbeused
beforechildrendowrittensums.
D Soon 25 more birds flew in. Let us add to see how many
birds in all there are now.
For 16 + 25 we write:
+
10
1
10 10 1 1 1 1 1
10
1 1 1
1 1 1
1 6
2 5
+
10
1
10 10 1 1 1 1 1
10
1 1 1
1 1 1
10
1 6
2 5
1
1
+
10
1
10 10 1
10 10
1 6
2 5
4 1
1
Putting all the      s
together, we get
eleven      s. Of
those, ten      s
make one .
And we are left
with one .
1
10
1
1
1
Now putting together
all the       s, we get
four       s.
10
10
113
2019-20
114
In the same way, we will add the number of swans
and cranes.
Also try adding
without writing.
The total number of swans and cranes is ___________.
Number of Swans
Number of Cranes
+
10
1
3 9
3 1
10 10 10 1
1 1 1 1 1
1 1 1 1
10 10 10
Suraj, don't be sad!
Let us hope they
come back next year.
115
There are
31 cranes and
39 swans.
Let us find out
how many swans
and cranes
there are in all.
How Many Cranes and Swans?
2019-20
114
Also try adding
without writing.
_____________ birds have gone away.
Suraj, don't be sad!
Let us hope they
come back next year.
115
–
10
1
7 0
2 6
10 10
1 1 1
1 1 1
10 10 10 10
10 10 10
One morning, Suraj saw that out of 70 birds only 26
birds were left. The rest had gone away.
How many birds have gone away? D
There are
31 cranes and
39 swans.
Let us find out
how many swans
and cranes
there are in all.
How Many Cranes and Swans?
2019-20