1. A stadium has 19,850 seats. For a concert, 12,125 tickets were sold, but 2,950 seats were later added. Estimate the final number of available seats by rounding to the nearest thousand. The estimated number of seats is ___.
2. A farmer harvests 88,450 pounds of potatoes. He sells 21,800 pounds to one buyer and 9,950 pounds to another. Which is the most reasonable estimate for the remaining pounds, rounding to the nearest ten thousand?
3. A calculation shows the precise answer to a problem is 35,275. An estimate for the same problem, found by rounding to the nearest thousand, is 35,000. The difference between the precise answer and the estimate is ___.
4. A factory made 121,500 parts, then shipped 39,880 and 9,540. A worker calculated 72,080 parts remain. Is this answer reasonable when compared to an estimate rounded to the nearest ten thousand?
5. A charity raised $32,125$ from a gala and $8,950$ from an auction, for a precise total of $41,075. To check if this total is reasonable, you can estimate the sum by rounding to the nearest thousand. The estimated total is ___ dollars. (include comma)
6. Estimate the sum of $68,240 + 21,990$ by rounding each number to the nearest ten thousand. The estimated sum is ___.
7. Which of the following is the best estimate for the sum $4,815 + 2,350$ when rounding to the nearest thousand?
8. Estimate the difference $912,800 - 489,150$ by rounding each number to the nearest hundred thousand. The estimated difference is ___.
9. A company sold 88,490 widgets last year and 32,710 widgets this year. Estimate the difference by rounding each number to the nearest ten thousand.
10. A warehouse received two shipments weighing 148,250 pounds and 354,900 pounds. Estimate the total weight by rounding each number to the nearest hundred thousand. The estimated total is ___ pounds.