Problem: 12,345 + 23,456
Answer: 35,801
You have 298 marbles, and your friend gives you 106 more. About how many marbles do you have now?
400 marbles (Estimate by rounding 298 to 300 and 106 to 100).
12,543 - 7,289
5,254
67,891 + 32,109
100,000
A school library has 682 books on the shelves. They donate 243 books to another school. About how many books are left in the library?
400 books (Estimate by rounding 682 to 700 and 243 to 200).
102,398 - 76,215
26,183
145,762 + 234,398
380,160
A movie theater sold 1,472 tickets on Friday and 1,256 tickets on Saturday. About how many tickets did they sell in total to the nearest hundred?
2,700 tickets (Estimate by rounding 1,472 to 1,500 and 1,256 to 1,200).
345,762 - 123,498
Answer: 222,264
456,789 + 123,456
580,245
A farmer planted 5,820 trees last year and 3,295 trees this year. About how many more trees were planted last year than this year?
2,500 trees (Estimate by rounding 5,820 to 6,000 and 3,295 to 3,500).
987,654 - 456,321
531,333
987,654 + 876,543
1,864,197
A town's population was 48,963 people last year. This year, the population increased by 21,487 people. About how many people live in the town now?
70,000 people (Estimate by rounding 48,963 to 50,000 and 21,487 to 20,000).