Zadanie 6,strona 26,Szkoła podstawowa,klasa 4 (podręcznik)

Oblicz:

a) 16 x 2             b) 23 x 4             c) 4 x 25            d) 4 x 54

2 x 45                 31 x 5                 28 x 6                36 x 5

84 x 2                 13 x 5                 8 x 19                77 x 2

3 x 25                 4 x 16                 7 x 13                3 x 44

Odpowiedz:

a)

16 x 2 = 32

2 x 45 = 90

84 x 2 = 168

3 x 25 = 75

b)

23 x 4 = (20 x 4) + (3 x 4) = 80 + 12 = 92

31 x 5 = 31 + 31 + 31 + 31 + 31 = 62 + 62 + 31 = 124 + 31 = 155

13 x 5 = 13 + 13 + 13 + 13 + 13 = 26 + 26 + 13 = 52 + 13 = 65

4 x 16 = 16 + 16 + 16 + 16 = 32 + 32 = 64

c)

4 x 25 = 25 + 25 + 25 + 25 = 50 + 50 = 100

28 x 6 = (20 x 6) + (8 x 6)  =120 + 48 = 168

8 x 19 = (8 x 10) + (8 x 9) = 80 + 72 = 152

7 x 13 = 13 + 13 + 13 + 13 + 13 + 13 +13 = 26 + 26 + 26 + 13 = 52 + 39 = 91

d)

4 x 54 = 54 + 54 + 54 + 54 = 108 + 108 = 216

36 x 5 = (30 x 5) + (6 x 5) = 150 + 30 = 180

77 x 2 = 77 + 77 = 154

3 x 44 = 44 + 44 + 44 = 88 + 44 = 132