Câu 2: Trang 137 - Toán tiếng anh lớp 5:Calculate:Tính:a) (3 hours 40 min + 2 hours 25 min) x 3(3...

a) Cách làm 1:
(3 hours 40 min + 2 hours 25 min) x 3
= (3 x 60 + 40 + 2 x 60 + 25) x 3
= (180 + 40 + 120 + 25) x 3
= 365 x 3
= 1095
= 18 hours 15 min

Cách làm 2:
(3 hours 40 min + 2 hours 25 min) x 3
= (3 + 2) hours + (40 + 25) min x 3
= 5 hours + 65 min x 3
= 5 hours + 195 min
= 5 hours + 3 hours 15 min
= 8 hours 15 min
= 8 x 60 + 15 min
= 495 min
= 18 hours 15 min

b) Cách làm:
3 hours 40 min + 2 hours 25 min x 3
= 3 x 60 + 40 + 2 x 60 + 25 x 3
= 180 + 40 + 120 + 75
= 240 + 195
= 435 min
= 7 hours 15 min
= 7 x 60 + 15 min
= 435 min
= 10 hours 55 min

c) Cách làm:
(5 min 35 sec + 6 min 21 sec) : 4
= (5 + 6) min + (35 + 21) sec : 4
= 11 min + 56 sec : 4
= 11 min + 14 sec
= 11 min + 14/60 min
= 11 min + 0.23 min
= 11 min 14.3 sec
= 11 min 14 sec

d) Cách làm:
12 min 3 sec x 2 + 4 min 12 sec : 4
= 24 min 6 sec + 256 sec : 4
= 24 min 6 sec + 64 sec
= 24 min 6 sec + 1 min 4 sec
= 25 min 10 sec
= 25 min 9 sec

Đáp án:
a) 18 hours 15 min
b) 10 hours 55 min
c) 11 min 14 sec
d) 25 min 9 sec.