Câu 2: Trang 66 - sách giáo khoa (SGK) Toán tiếng Anh lớp 4a) Calculated in two ways:Tính bằng hai...

a) Calculated in two ways:
36 x (7 + 3)
1st way:
36 x (7 + 3) = 36 x 10 = 360

2nd way:
36 x (7 + 3) = 36 x 7 + 36 x 3 = 252 + 108 = 360

207 x (2 + 6)
1st way:
207 x (2 + 6) = 207 x 8 = 1656

2nd way:
207 x (2 + 6) = 207 x 2 + 207 x 6 = 414 + 1242 = 1656

b) Calculated in two ways (using the model):
5 x 38 + 5 x 62
1st way:
5 x 38 + 5 x 62 = 5 x (38 + 62) = 5 x 100 = 500

2nd way:
5 x 38 + 5 x 62 = 190 + 310 = 500

135 x 8 + 135 x 2
1st way:
135 x 8 + 135 x 2 = 135 x (8 + 2) = 135 x 10 = 1350

2nd way:
135 x 8 + 135 x 2 = 1080 + 270 = 1350

Answer:
a)
36 x (7 + 3) = 360
207 x (2 + 6) = 1656

b)
5 x 38 + 5 x 62 = 500
135 x 8 + 135 x 2 = 1350