1, 249005024 consists of () million pieces and () million pieces. Reading and writing () is about () million in "ten thousand" and about () million in "hundred million".

The five numbers 2, 2, 3, 4, 7 and 5 make up the largest number () and the smallest number ().

3. Starting from one digit, the seventh digit is (), and the counting unit is ().

4.49 □ 785 ≈ 500,000, the maximum amount of □ can be filled in ().

5. When calculating 2 160 ÷ 20-57 with a calculator, press 2 160 on the keyboard, then press ÷, then press 20, and then press ÷-to display the screen ().

6. Five digits are rounded to10,000, and the digit is 80,000. The maximum value of this five-digit number is () and the minimum value is ().

7. "Little careless" miscalculated 28×(□+2) as 28×□+2, so the result is different from the correct answer ().

8.□÷2 1 = 35 ...△, where the maximum value is (), then □ is ().

9. There is a seven-digit number, and the number of digits of each number is 5. If you add 2 to this number, you will get a new seven-digit number. At this point, the sum of digits in this new number is 3, and the original number is ().