.


:




:

































 

 

 

 


III. . . 41 + 5 65 + 6 42 + 5 65 + 5 43 + 5 65 + 4 44 + 5




.

41 + 5   65 + 6
42 + 5   65 + 5
43 + 5   65 + 4
44 + 5   65 + 3
45 + 5   65 + 2
46 + 5   65 + 1

.

.

IV. .

1. 1.

. , .

45 + 7 = (40 + 5) + 7 = 40 + (5 + 7) = 40 + 12 = 52

? ( .)

? (.)

?

( 12.)

12 ?

( .)

: . .

.

2. 2.

, .

36 + 7 = (30 + 6) + 7 = 30 + (6 + 7) = 30 + 13 = 43

48 + 5 = (40 + 8) + 5 = 40 + (8 + 5) = 40 + 13 = 53

64 + 8 = (60 + 4) + 8 = 60 + (4 + 8) = 60 + 12 = 72

73 + 9 = (70 + 3) + 9 = 70 + (3 + 9) = 70 + 12 = 82

3. 3.

.

36 + 7 = 36 + (4 + 3) = (36 + 4) + 3 = 40 + 3 = 43

48 + 5 = 48 + (2 + 3) = (48 + 2) + 3 = 50 + 3 = 53

64 + 8 = 64 + (6 + 2) = (64 + 6) + 2 = 70 + 2 = 72

73 + 9 = 73 + (7 + 2) = (73 + 7) + 2 = 80 + 2 = 82

4. 4.

, 25 + 8.

:

25 .

8 .

? .

: 25 + 8 = 33 (.) .

: 33 .

5. 5.

.

? ?

, .

1- 18 .

2- 6 .

? .

: 18 + 6 = 24 (.) .

: 24 .

6. 7.

.

?

.

 + ( + ) ( ) +   + ( )

7 + (30 + 14) = 51 (68 40) + 3 = 31 4 + (89 20) = 83

9 + (54 + 20) = 83 (57 30) + 6 = 33 5 + (75 40) = 40

7. 8.

.

:

26 .

8 .

? .

:

26 + 8 = 34 () .

: 34 .

V. .

?

?

: , . 58, 6.

28

: ; ; ; ; .

I. .

II. .

1. , :

) 3, 8, 38, 4, 7, 47, 5, 6, 56,

) 3, 5, 53, 4, 6, 64, 5, 7, 75,

) 35, 38, 41, 44, 47, 50,

2. , :

3 +  = 9  + 4 = 94 4 +  = 7
7 +  = 8  + 7 = 67 3 +  = 6
2 +  = 5  + 5 = 85 3 +  = 33

3. .

60 , 20. ?

4. ?

III. .

.

40 6   39 5
27 6   86 5
89 6   70 5
67 6   57 5

?

.

IV. .

1. 1.

?

. .

37 + 3 = 40 55 + 5 = 60 63 + 7 =70

24 + 6 = 30 31 + 9 = 40 76 + 4 =80

48 + 2 = 50 82 + 8 = 90

2. 2.

, . .

37 + 3 = 40 40 3 = 37

31 + 9 = 40 40 9 = 31

24 + 6 = 30 30 6 = 24

82 + 8 = 90 90 8 = 82

48 + 2 = 50 50 2 = 48

63 + 7 = 70 70 7 = 63

76 + 4 = 80 80 4 = 76

?

3. 3.

.

4. 4.

, .

40 3 = (30 + 10) 3 = 30 + (10 3) = 30 + 7 = 37

.

70 3 = (60 + 10) 3 = 60 + (10 3) = 60 + 7 = 67

60 2 = (50 + 10) 2 = 50 + (10 2) = 50 + 8 = 58

70 8 = (60 + 10) 8 = 60 + (10 8) = 60 + 2 = 62

40 7 = (30 + 10) 7 = 30 + (10 7) = 30 + 3 = 33

50 4 = (40 + 10) 4 = 40 + (10 4) = 40 + 4 = 44

5. 5.

, , 7.

.

20 7 = 13

30 7 = 23

40 7 = 33

50 7 = 43

60 7 = 53

. ( 1.)

6. 6.

, . .

50 4 > 50 8 70 7 < 70 2 80 4 > 70 4

, .

7. 7.

, 30 8.

:

30 .

8 .

? .

:

30 8 = 22 (.) .

: 22 .

, .

8. .

, , 13.

V. .

?

?

: , 50 7.

 

 

29

: ; ; ; .





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