To estimate sums and differences to the nearest ten, we follow these steps for each problem:
1.
Round each number to the nearest ten. (If the ones digit is 5 or more, round up. If it is less than 5, round down).
2.
Add or
subtract the rounded numbers.
Here are the solutions for problems 2 through 14:
2) 498 - 183
* Round 498 to
500.
* Round 183 to
180.
* Subtract: $500 - 180 = 320$.
3) 542 - 244
* Round 542 to
540.
* Round 244 to
240.
* Subtract: $540 - 240 = 300$.
4) 827 - 792
* Round 827 to
830.
* Round 792 to
790.
* Subtract: $830 - 790 = 40$.
5) 914 + 746
* Round 914 to
910.
* Round 746 to
750.
* Add: $910 + 750 = 1660$.
6) 616 - 454
* Round 616 to
620.
* Round 454 to
450.
* Subtract: $620 - 450 = 170$.
7) 369 + 159
* Round 369 to
370.
* Round 159 to
160.
* Add: $370 + 160 = 530$.
8) 777 - 466
* Round 777 to
780.
* Round 466 to
470.
* Subtract: $780 - 470 = 310$.
9) 226 + 526
* Round 226 to
230.
* Round 526 to
530.
* Add: $230 + 530 = 760$.
10) 949 + 123
* Round 949 to
950.
* Round 123 to
120.
* Add: $950 + 120 = 1070$.
11) 839 - 342
* Round 839 to
840.
* Round 342 to
340.
* Subtract: $840 - 340 = 500$.
12) 836 + 845
* Round 836 to
840.
* Round 845 to
850.
* Add: $840 + 850 = 1690$.
13) 458 + 467
* Round 458 to
460.
* Round 467 to
470.
* Add: $460 + 470 = 930$.
14) 784 - 395
* Round 784 to
780.
* Round 395 to
400.
* Subtract: $780 - 400 = 380$.
Final Answer:
2) 320
3) 300
4) 40
5) 1660
6) 170
7) 530
8) 310
9) 760
10) 1070
11) 500
12) 1690
13) 930
14) 380
Parent Tip: Review the logic above to help your child master the concept of estimation worksheet for 3rd grade.
