Bai 1:mot hinh chu nhat co chu vi 9/10m, chieu dai hon chieu rong 1/20 m. tinh dien tich hinh chu nhat do.
bai 2 : a, 832 900 dag=...... ta ......kg
b, 16 giay=..... phut ........giay
c, 4000 nam=.........the ki
d, 1/20kg=..........g
e, 3/5 yen=............. hg
g, 5/4 the ki=.......... nam
h, 1/6 ngay=..........gio