Let’s solve each multiplication problem step by step. We’ll multiply the three-digit numbers carefully, one at a time.
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1) 420 × 426
Break it down:
- 420 × 400 = 168,000
- 420 × 20 = 8,400
- 420 × 6 = 2,520
Add them: 168,000 + 8,400 = 176,400 → +2,520 =
178,920
✔ Check with calculator-style:
420 × 426 = (400+20)(400+26) — but easier to just compute directly:
420 × 426 = 178,920 ✔️
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2) 333 × 390
Note: 390 = 39 × 10 → so do 333 × 39 first, then add a zero.
333 × 39:
- 333 × 30 = 9,990
- 333 × 9 = 2,997
Add: 9,990 + 2,997 = 12,987 → now add zero →
129,870
✔ 333 × 390 = 129,870 ✔️
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3) 990 × 856
Think of 990 as 1000 - 10 → use distributive property:
(1000 - 10) × 856 = 1000×856 - 10×856 = 856,000 - 8,560 =
847,440
✔ 990 × 856 = 847,440 ✔️
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4) 243 × 426
Use standard multiplication:
First, 243 × 6 = 1,458
Then, 243 × 20 = 4,860
Then, 243 × 400 = 97,200
Add:
1,458
+4,860 → 6,318
+97,200 →
103,518
✔ 243 × 426 = 103,518 ✔️
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5) 645 × 835
This is big — break into parts:
645 × 800 = 516,000
645 × 30 = 19,350
645 × 5 = 3,225
Add:
516,000 + 19,350 = 535,350
+3,225 =
538,575
✔ 645 × 835 = 538,575 ✔️
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6) 954 × 759
Break 759 into 700 + 50 + 9
954 × 700 = 667,800
954 × 50 = 47,700
954 × 9 = 8,586
Add:
667,800 + 47,700 = 715,500
+8,586 =
724,086
✔ 954 × 759 = 724,086 ✔️
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7) 240 × 783
240 × 700 = 168,000
240 × 80 = 19,200
240 × 3 = 720
Add:
168,000 + 19,200 = 187,200
+720 =
187,920
✔ 240 × 783 = 187,920 ✔️
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8) 420 × 893
420 × 800 = 336,000
420 × 90 = 37,800
420 × 3 = 1,260
Add:
336,000 + 37,800 = 373,800
+1,260 =
375,060
✔ 420 × 893 = 375,060 ✔️
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9) 125 × 603
125 × 600 = 75,000
125 × 3 = 375
Total:
75,375
✔ 125 × 603 = 75,375 ✔️
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10) 718 × 342
Break 342 into 300 + 40 + 2
718 × 300 = 215,400
718 × 40 = 28,720
718 × 2 = 1,436
Add:
215,400 + 28,720 = 244,120
+1,436 =
245,556
✔ 718 × 342 = 245,556 ✔️
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11) 548 × 785
Break 785 into 700 + 80 + 5
548 × 700 = 383,600
548 × 80 = 43,840
548 × 5 = 2,740
Add:
383,600 + 43,840 = 427,440
+2,740 =
430,180
✔ 548 × 785 = 430,180 ✔️
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12) 391 × 688
Break 688 into 600 + 80 + 8
391 × 600 = 234,600
391 × 80 = 31,280
391 × 8 = 3,128
Add:
234,600 + 31,280 = 265,880
+3,128 =
269,008
✔ 391 × 688 = 269,008 ✔️
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13) 420 × 174
420 × 100 = 42,000
420 × 70 = 29,400
420 × 4 = 1,680
Add:
42,000 + 29,400 = 71,400
+1,680 =
73,080
✔ 420 × 174 = 73,080 ✔️
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14) 915 × 361
Break 361 into 300 + 60 + 1
915 × 300 = 274,500
915 × 60 = 54,900
915 × 1 = 915
Add:
274,500 + 54,900 = 329,400
+915 =
330,315
✔ 915 × 361 = 330,315 ✔️
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15) 972 × 559
Break 559 into 500 + 50 + 9
972 × 500 = 486,000
972 × 50 = 48,600
972 × 9 = 8,748
Add:
486,000 + 48,600 = 534,600
+8,748 =
543,348
✔ 972 × 559 = 543,348 ✔️
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Final Answer:
1) 178,920
2) 129,870
3) 847,440
4) 103,518
5) 538,575
6) 724,086
7) 187,920
8) 375,060
9) 75,375
10) 245,556
11) 430,180
12) 269,008
13) 73,080
14) 330,315
15) 543,348
Parent Tip: Review the logic above to help your child master the concept of 3 digit multiplication worksheet grade 5.
