Use the method of rounding, take the approximate value of each number according to the requirements, and use the scientific counting method to express 12 200 000 000 (keep 2 significant figures) 361059000 (keep three significant figures) 11669.4 billion (keep 4 significant figures) 9500 (accurate to 100 million bits) 42 million (to the nearest million)
1.2*10^10
3.61 * 104000 = 3.61 * 104000
167 * 10 ^ 5 million = 167 * 10 ^ 13 million
9.5000 * 10 ^ 12 = 9.5 * 10 ^ 4 billion
4.2 million = 4.2 * 10 ^ 7