Что узнали. Чему научились
1)
32 + 45 = (30 + 2) + (40 + 5) = (30 + 40) + (2 + 5) = 70 + 7 = 77
68 — 43 = (60 + 8) — (40 + 3) = (60 — 40) + (8 — 3) = 20 + 5 — 25
54 + 13 = (50 + 4) + (10 + 3) = (50 + 10) + (4 + 3) = 60 + 7 = 67
79 — 56 = (70 + 9) — (50 + 6) = (70 — 50) + (9 — 6) = 20 + 3 = 23
2)
3)
a + 8 14 + 8 = 22 8 + 8 = 16 6 + 8 = 14 0 + 8 = 8
|
b — 6 13 — 6 = 7 18 — 6 = 12 44 — 6 = 38 50 — 6 = 44
|
15 — x = 8 15 — 7 = 8 x = 7
|
21 — x = 20 21 — 1 = 20 x = 1 |
15 — x = 5 15 — 10 = 5 x = 10 |
13 — x = 7 13 — 6 = 7 x = 6 |
14 — x = 7 14 — 7 = 7 x = 7
|
16 — x = 9 16 — 7 = 9 x = 7 |
x + 40 = 47 7 + 40 = 47 x = 7
|
17 — x = 10 17 — 7 = 10 x = 7
|
27 — x = 20 27 — 7 = 20 x = 7
|
21 — 14 = 7
7 + 14 = 21
14 + 7 < 21 + 8 21 - 7 < 14 + 8
80 — (24 — 6) — 80 — 18 — 62
90 — (36 — 8) = 90 — 28 = 62
48 + (13 + 7) = 48 + 20 = 68
34 + (18 + 2) = 34 + 20 = 54
89 — (64 — 4) = 89 — 60 = 29
75 — (37 — 7) = 75 — 30 = 45
8 + 7 — 6 = 15 — 6 = 9
4 + 9 — 7 = 13 — 7 = 6
12 — 7 + 9 = 5 + 9 = 14
16 — 8 + 9 = 8 + 9 = 17
6 + 6 — 8 = 12 — 8 = 4
7 + 7 — 5 = 14 — 5 = 9
8 + 4 + 4
= 16
7 + 9 + 4
= 20
15 — 7
— 8 = 0
17 — 7
— 10 = 0
9 + 0 + 11
= 20
9 — 9
+ 15 = 15
Ребусы.