Easy Addition Problems

This will be problems such as 40 + 3, 60 + 20, 42 + 7, 34 + 20.
Addition
e. g. 40 + 3
To solve a problem like 40 + 3, use the system of numeration.
40 = 4 tens
3 = 3 ones
4 tens + 3 ones = 43 ones
This is called the system of numeration [addition and place value]
So, 40 + 3 = 43

Solve these problems using the above method
Practice 1:
20 + 8
20 = 2 tens
8 = (8) ones
2 tens + (8) ones = (28) ones

Practice 2:
60 + 7
(6) tens + (7) ones = (67) ones
(67) ones = (67)

Solve Mentally:
1. 30 + 3
2. 20 + 6
3. 90 + 1
4. 40 + 8

e. g. 60 + 20
To solve a problem like 60 + 20, take the tens digits as ones and add them.
60 ones = 6 tens
20 ones = 2 tens
6 tens + 2 tens = 8 tens
8 tens = 80
So, 60 + 20 = 80

Solve these problems using the above method
Practice 1:
40 + 30
40 ones = 4 tens
30 ones = (3) tens
4 tens + (3) tens = (7) tens
(7) tens = (70) ones

Practice 2:
50 + 40
(5) tens + (4) tens = (9) tens
(9) tens = (90) ones

Solve mentally:
1. 30 + 40
2. 60 + 20
3. 10 + 80
4. 40 + 50

e. g. 42 + 7
To solve a problem like 42 + 7, split the 42 into ones and tens and add the ones together. Then use system of numeration to add tens and ones.
42 = 40 + 2
2 + 7 = 9
40 + 9 = 49
So, 42 + 7 = 49

Solve these problems using the above method
Practice 1:
42 + 6
42 = (40) + (2)
(2) + 6 = (8)
40 + (8) = (48)

Practice 2:
73 + 5
73 = (70) + (3)
(3) + (5) = (8)
(70) + (8) = (78)

Solve Mentally:
1. 33 + 3
2. 67 + 2
3. 71 + 8
4. 91 + 7
5. 57 + 2
6. 83 + 6

e. g. 34 + 20
To solve a problem like 34 + 20, split the 34 into ones and tens and add the tens. Then use system of numeration to add tens and ones.
34 = 30 + 4
30 + 20 = 50
50 + 4 = 54
So, 34 + 20 = 54

Solve these problems using the above method.
Practice 1:
42 + 30
42 = (40) + 2
(40) + 30 = (70)
(70) + 2 = (72)

Practice 2:
43 + 50
43 = (40) + (3)
(40) + (50) = (90)
(90) + (3) = (93)

Solve Mentally:
1. 34 + 30
2. 57 + 20
3. 12 + 80
4. 21 + 70
5. 43 + 20
6. 53 + 30