Current location - Training Enrollment Network - Mathematics courses - Fill in the appropriate units. The cover area of the math textbook is about 4 _ _ _ _ Xiaoming sleeps about 9 _ _ _ every day. The area of a hundred-dollar bill is about 1 1.
Fill in the appropriate units. The cover area of the math textbook is about 4 _ _ _ _ Xiaoming sleeps about 9 _ _ _ every day. The area of a hundred-dollar bill is about 1 1.
The area of the cover of the math textbook is about 4 square decimeters;

Xiao Ming sleeps about 9 hours every day;

The area of a hundred-dollar bill is about 1 10 square centimeter;

A building is about 16 meters high.

So the answer is: square decimeter; Hours; Square centimeter; rice.