Let’s solve each problem one by one. We’ll do addition and subtraction carefully, lining up the numbers by place value (hundreds, tens, ones).
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Row 1:
1.
206 + 12
→ 206 + 10 = 216, then +2 =
218
2.
329 + 325
→ 300 + 300 = 600
→ 29 + 25 = 54
→ 600 + 54 =
654
3.
810 + 65
→ 810 + 60 = 870, then +5 =
875
4.
355 – 121
→ 355 – 100 = 255, then –21 = 234 →
234
5.
157 – 96
→ 157 – 90 = 67, then –6 =
61
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Row 2:
6.
687 – 390
→ 687 – 300 = 387, then –90 = 297 →
297
7.
632 – 65
→ 632 – 60 = 572, then –5 =
567
8.
978 + 979
→ 900 + 900 = 1800
→ 78 + 79 = 157
→ 1800 + 157 =
1957
9.
785 – 465
→ 785 – 400 = 385, then –65 = 320 →
320
10.
429 – 215
→ 429 – 200 = 229, then –15 =
214
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Row 3:
11.
504 – 272
→ 504 – 200 = 304, then –72 = 232 →
232
12.
988 + 228
→ 900 + 200 = 1100
→ 88 + 28 = 116
→ 1100 + 116 =
1216
13.
880 + 45
→ 880 + 40 = 920, then +5 =
925
14.
159 + 27
→ 159 + 20 = 177, then +7 =
184
15.
398 – 73
→ 398 – 70 = 328, then –3 =
325
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Row 4:
16.
974 – 914
→ 974 – 900 = 74, then –14 =
60
17.
251 + 57
→ 251 + 50 = 301, then +7 =
308
18.
143 – 73
→ 143 – 70 = 73, then –3 =
70
19.
674 + 86
→ 674 + 80 = 754, then +6 =
760
20.
224 – 10
→ 224 – 10 =
214
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Row 5:
21.
661 + 680
→ 600 + 600 = 1200
→ 61 + 80 = 141
→ 1200 + 141 =
1341
22.
327 + 859
→ 300 + 800 = 1100
→ 27 + 59 = 86
→ 1100 + 86 =
1186
23.
269 – 132
→ 269 – 100 = 169, then –32 = 137 →
137
24.
665 + 932
→ 600 + 900 = 1500
→ 65 + 32 = 97
→ 1500 + 97 =
1597
25.
482 + 21
→ 482 + 20 = 502, then +1 =
503
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Final Answer:
218, 654, 875, 234, 61, 297, 567, 1957, 320, 214, 232, 1216, 925, 184, 325, 60, 308, 70, 760, 214, 1341, 1186, 137, 1597, 503
Parent Tip: Review the logic above to help your child master the concept of 3 digit addition and subtraction worksheet.
