1. 1 It is known that China's land area is about 9.6 million square kilometers (9.6 million square kilometers).

174.3 1÷960× 100% ≈ 18.2%

29.6 million square kilometers = 9.6 million square kilometers.

2460÷9600000≈0.03%

2. Q: During the period of 1990- 1995, what percentage did the world's forest resources decrease compared with 1995?

A: 3.454 billion hectares = 3.454 billion hectares.

5630÷345400≈ 1.6%

Extension:

1 mu = 666.67m2.

1 m2 = 0.0015mu

1 hectare = 1 00 00 mu = 15 mu.

1 mu = 100 square meter