Numbers up to 50
5.Climb up the ladder with the
numbers in ­increasing order.
Example: 40, 36, 21, 28, 48
a. 27, 12, 35, 33, 47
b. 50, 19, 25, 37, 41
c. 33, 22, 27, 42, 15
48
a.
b.
Chapter 1
Increasing
order is also
called as
‘ascending
order’.
c.
N
40
36
28
21
6.Climb down the ladder with the
numbers in decreasing order.
Example:26, 28, 42, 37, 39
a. 20, 39, 43, 28, 12
b. 46, 32, 38, 29, 9
c. 49, 36, 39, 24, 46
42
a.
b.
39
37
28
26
13
c.
Decreasing
order is also
called as
‘descending
order’.
Chapter 1
Numbers up to 50
Exercise 8
1.Write the expanded form of numbers.
Expanded form
N
24= 2 tens+ 4 units= 20 + 4
a. 45=
tens+
units=
+
b. 38=
tens+
units=
+
c. 18=
ten +
units=
+
d. 50=
tens+
units=
+
Mental Math
Write the standard form of the number.
a. 3 tens + 5 units =
b. 40 + 3 =
c. 1 ten + 1 unit =
d. 20 + 9 =
e. 2 tens + 0 unit =
f. 50 + 0 =
14
Numbers up to 50
Chapter 1
2.Form the largest and smallest 2-digit ­numbers
using the given digits.
To form the
smallest number,
use the smaller
digit at the tens
place.
To form the
largest number,
use the larger digit
at the tens
place.
Digits
2 and 4
Smallest
Largest
2-digit number 2-digit number
24
42
a. 3 and 1
b. 1 and 0
c. 3 and 4
While forming 2-digit numbers, why is it
not possible to write 0 at the tens place?
_______________________________
_______________________________
15
N
Chapter 1
Numbers up to 50
Look at the position of the children
sitting in the toy train.
N
Ninth
9th
Tenth
10th
Fourth
4th
Third
3rd
ordinal
numbers.
Eighth Seventh
8th
7th
Sixth
6th
Fifth
5th
Second
2nd
First
1st
Exercise 9
Circle the position of the objects.
a.
Second
b.
First
c.
Fifth
16
Chapter 2
Numbers (N)
Number Concept (N1)
N
Numbers up to 100
This is an abacus. It has a tens rod
and a units rod.
T U
1 bead is in the tens rod = 1 ten
6 beads are in the units rod = 6 units
So, 1 ten + 6 units = 16
T U
Here, 2 tens + 4 units = 24
T U
4 tens + 2 units = 42
T U
In an abacus, the number of beads in the
units rod represents the number at the units
place and the number of beads in the tens rod
represents the number at the tens place of
the 2-digit number.
Learn numbers beyond 50 and then represent
them on the abacus.
17
Chapter 2
Numbers up to 100
Let us learn about numbers beyond 50.
Numbers from 51 to 60
N
Tens
Units
5
1
5
Number name
Numbers from
Tens
Units
Fifty-one
6
1
2
Fifty-two
6
2
5
3
Fifty-three
6
3
5
4
Fifty-four
6
4
5
5
Fifty-five
6
5
5
6
Fifty-six
6
6
5
7
Fifty-seven
6
7
5
8
Fifty-eight
6
8
5
9
Fifty-nine
6
9
6
0
Sixty
7
0
18
Numbers up to 100
61 to 70
Number name
Chapter 2
Numbers from 71 to 80
Tens
Units
Sixty-one
7
1
Seventy-one
Sixty-two
7
2
Seventy-two
Sixty-three
7
3
Seventy-three
Sixty-four
7
4
Seventy-four
Sixty-five
7
5
Seventy-five
Sixty-six
7
6
Seventy-six
Sixty-seven
7
7
Seventy-seven
Sixty-eight
7
8
Seventy-eight
Sixty-nine
7
9
Seventy-nine
Seventy
8
0
Eighty
19
Number name
N
Chapter 2
Numbers up to 100
Exercise 1
1. Match the number names with the numbers.
Sixty-five
N
68 Sixty-six74
Seventy-three 70 Seventy-six
Sixty-eight
65 Seventy-four 57
Seventy
59 Fifty-two66
Fifty-nine
73 Fifty-seven
2. Write the number names.
a. b. c. d. 55
69
73
66
20
52
76
Numbers up to 100
Chapter 2
Numbers from 81 to 90
Tens
Units
8
1
Number name
Eighty-one
8
2
Eighty-two
8
3
Eighty-three
8
4
Eighty-four
8
5
Eighty-five
8
6
Eighty-six
8
7
Eighty-seven
8
8
Eighty-eight
8
9
Eighty-nine
9
0
Ninety
21
N
Chapter 2
Numbers up to 100
Numbers from 91 to 100
N
Tens
Units
Number name
9
1
Ninety-one
9
2
Ninety-two
9
3
Ninety-three
9
4
Ninety-four
9
5
Ninety-five
9
6
Ninety-six
9
7
Ninety-seven
9
8
Ninety-eight
9
9
Ninety-nine
Hundreds Tens
1
0
Units
0
The number 99
has digits at
the units place
and the tens
place. After 99
a new place is
added in the
chart. This
place is called
the hundreds
place. The new
number formed
is 100.
Number name
One Hundred
22
Numbers up to 100
Chapter 2
Exercise 2
1.Fill in the missing numbers to complete the
forward counting.
1
10 Here
we are
12
19
moving
23
28
forward or
34
37
backward
45 46
by units.
55 56
This
means we
64
67
are skip
73
78
counting
82
89
by ones!
91
100
2.Fill in the missing numbers to complete the
backward counting.
100
10
89
19
78
28
67
37
56 55
46 45
23
64
34
73
23
82
12
91
1
N
Chapter 2
Numbers up to 100
3. Write the numbers.
N
a. Sixty-four
b. Eighty-eight
c. Seventy-one
d. Fifty-five
e. Sixty-nine
f. Ninety-three
4. Skip count as instructed.
Counting by twos
a.
68
58 60
b.
38 36
46
Counting by fives
a.55 60
75
b.65
30 25
24
Numbers up to 100
Chapter 2
Counting by tens
a.10
20
60
b.30
N
Exercise 3
1.Write the number that comes just before the
given number.
a. 50
b. 96
c. 93
d. 89
e. 74
f. 80
2.Write the number that comes just after the
given number.
a. 59
b. 62
c. 50
d. 89
e. 99
f. 71
3. Write the missing number(s).
a.
86
c.
88 b.
94
d.73
25
29
75
Chapter 2
Numbers up to 100
4.Compare the numbers using <, > or =.
N
a. 57 75
b. 96 69
c. 46 66
d. 79 97
e. 77 77
f. 80 84
5.Climb up the stairs with the numbers in
ascending order.
a. 100, 66, 77, 89 b. 86, 68, 49, 96
6.Climb down the stairs with the numbers in
descending order.
a. 93, 46, 84, 77 b. 69, 55, 96, 84
26
Numbers up to 100
Chapter 2
Exercise 4
1.Write the expanded form of numbers.
Expanded form
95= 9 tens+ 5 units= 90 + 5
a. 64=
tens+
units=
+ b. 70=
tens+
units=
+ c. 69=
tens+
units=
+ Mental Math
Represent the number on the abacus.
a. 80 + 4 b. 5 tens + 2 units c. 69
H
T
U
H
T
27
U
H
T
U
N
Chapter 2
Numbers up to 100
2.Form the largest and smallest 2-digit
numbers using the given digits.
N
Digits
Smallest
2-digit
number
Largest
2-digit
number
1 and 7
17
71
a. 4 and 8
b. 2 and 6
c. 5 and 9
To form the largest number, use the larger
digit at the tens place.
To form the smallest number, use the
smaller digit at the tens place.
A number with 0 at the tens position cannot
be called a 2-digit number as zero means
nothing, so it means that no digit holds
the value at that place. In such a case, it is
a 1-digit number.
28