1. The problem asks to convert numbers between standard form, expanded form, and English or Chinese words. 2. For part (a), the expanded form of 349007.9 means writing it as the sum of each digit times its place value. 3. For part (b), the standard form of "six hundred forty-two thousand thirty-one" is writing the number in digits. 4. For part (c), writing 904862 in English words means spelling out the number. 5. For part (d), writing 890431 in Chinese means expressing the number in Chinese numerals. 6. For part (e), the standard form of the sum 500000 + 70000 + 2000 + 600 + 10 + 3 + 0.1 + 0.09 is the total sum written as a single number. Step-by-step solutions: 1. (a) Expanded form of 349007.9: $$349007.9 = 300000 + 40000 + 9000 + 0 + 0 + 7 + 0.9$$ 2. (b) Standard form of "six hundred forty-two thousand thirty-one": $$642031$$ 3. (c) English words for 904862: "nine hundred four thousand eight hundred sixty-two" 4. (d) Chinese for 890431: "八十九万零四百三十一" 5. (e) Sum the parts: $$500000 + 70000 + 2000 + 600 + 10 + 3 + 0.1 + 0.09 = 572613.19$$ Final answers: (a) $300000 + 40000 + 9000 + 0 + 0 + 7 + 0.9$ (b) $642031$ (c) "nine hundred four thousand eight hundred sixty-two" (d) "八十九万零四百三十一" (e) $572613.19$