Vở bài tập Toán lớp 4 trang 83 Kết nối tri thức

a) 8 + 9 + 2 = ……………….

                   = ……………….

                   = ……………….

b) 28 + 93 + 72 = ……………….

                          = ……………….

                          = ……………….

c) 90 + 76 + 10 = ……………….

                          = ……………….

                          = ……………….

d) 50 + 98 + 50 = ……………….

                          = ……………….

                          = ……………….

a) 8 + 9 + 2 = (8 + 2) + 9

                   = 10 + 9

                   = 19

b) 28 + 93 + 72 = (28 + 72) + 93

                          = 100 + 93

                          = 193

c) 90 + 76 + 10 = (90 + 10) + 76

                          = 100 + 76

                          = 176

d) 50 + 98 + 50 = (50 + 50) + 98

                          = 100 + 98

                          = 198

83 + 450 + 50 = ……………….

                       = ……………….

                       = ……………….

25 + 982 + 75   = ……………….

                          = ……………….

                          = ……………….

800 + 381 + 200 = ……………….

                           = ……………….

                           = ……………….

70 + 75 + 30 + 25 = ……………….

                             = ……………….

                             = ……………….

83 + 450 + 50 = 83 + (450 + 50)

                       = 83 + 500

                       = 583

25 + 982 + 75   = (25 + 75) + 982

                          = 100 + 982

                          = 1 082

800 + 381 + 200 = (800 + 200) + 381

                           = 1 000 + 381

                           = 1 381

70 + 75 + 30 + 25 = (70 + 30) + (75 + 25)

                             = 100 + 100

                             = 200

81 + 3 + a = ….. + 3 + 81

(92 + 73) + 8 = ….. + (8 + 92)

a + (b + c) = (a + …..) + c

a + b + c + d = a + b + (….. + d)

81 + 3 + a = a + 3 + 81

(92 + 73) + 8 = 73 + (8 + 92)

a + (b + c) = (a + b) + c

a + b + c + d = a + b + (c + d)