Answer: 1, 360 square centimeters, 78 centimeters, 12 decimeters, 40 decimeters, 4 meters, 18 meters, 50 centimeters, 1000 square centimeters; 49 square centimeters, 28 centimeters, 8 decimeters, 32 decimeters, 30 meters, 900 square meters, 120 meters.

2 、( 1)D

⑵D

(3)C

3、(55- 15)? 2=20 (meters); 20? 15 = 300m2

4、24? 4=6 (decimeter); 62=36 (square decimeter)

5. Circumstance: 280cm；; Area: 4050 square centimeters