Reference home / Curriculum / 3A / Chapter 5

Educator and learner reference

Complete Chapter 5 answer key

Full answers and reasoning for every chapter lesson and assessment.

Print this separately when students work on assessment pages. These are publicly available explanatory solutions, not secure school answers.

Lesson 1: Multiplying Ones, Tens, and Hundreds

Entry

  1. 114 — (50+7)×2=(50×2)+(7×2)=114.
  2. 192 — (60+4)×3=(60×3)+(4×3)=192.

Worked checks

  1. 4000 — 800 is 8 groups of 100; 5×8=40 groups of 100 equals 4,000.
  2. 120 — 20 is 2 groups of 10; 6×2=12 groups of 10 equals 120.
  3. 3500 — 500 is 5 groups of 100; 7×5=35 groups of 100 equals 3,500.

Guided

  1. 3200 — 800 is 8 groups of 100; 4×8=32 groups of 100 equals 3,200.
  2. 100 — 20 is 2 groups of 10; 5×2=10 groups of 10 equals 100.
  3. 3000 — 500 is 5 groups of 100; 6×5=30 groups of 100 equals 3,000.
  4. 560 — 80 is 8 groups of 10; 7×8=56 groups of 10 equals 560.

Independent

  1. 1000 — 500 is 5 groups of 100; 2×5=10 groups of 100 equals 1,000.
  2. 240 — 80 is 8 groups of 10; 3×8=24 groups of 10 equals 240.
  3. 800 — 200 is 2 groups of 100; 4×2=8 groups of 100 equals 800.
  4. 250 — 50 is 5 groups of 10; 5×5=25 groups of 10 equals 250.
  5. 4800 — 800 is 8 groups of 100; 6×8=48 groups of 100 equals 4,800.
  6. 140 — 20 is 2 groups of 10; 7×2=14 groups of 10 equals 140.
  7. 4000 — 500 is 5 groups of 100; 8×5=40 groups of 100 equals 4,000.
  8. 160 — 80 is 8 groups of 10; 2×8=16 groups of 10 equals 160.

Challenge

  1. Because 40 is four tens — 6×4 tens=24 tens, and 24 tens=240 ones.
  2. 560 — 8×7 tens=56 tens=560. The product must be hundreds, not tens or thousands.

Exit

  1. 4000 — 800 is 8 groups of 100; 5×8=40 groups of 100 equals 4,000.
  2. 120 — 20 is 2 groups of 10; 6×2=12 groups of 10 equals 120.
  3. 3500 — 500 is 5 groups of 100; 7×5=35 groups of 100 equals 3,500.

Lesson 2: Multiplication Without Regrouping

Entry

  1. 2500 — 500 is 5 groups of 100; 5×5=25 groups of 100 equals 2,500.
  2. 480 — 80 is 8 groups of 10; 6×8=48 groups of 10 equals 480.

Worked checks

  1. 993 — Split 331 by place value; multiply each part by 3 and add. Total is 993.
  2. 622 — Split 311 by place value; multiply each part by 2 and add. Total is 622.
  3. 933 — Split 311 by place value; multiply each part by 3 and add. Total is 933.

Guided

  1. 62 — Split 31 by place value; multiply each part by 2 and add. Total is 62.
  2. 93 — Split 31 by place value; multiply each part by 3 and add. Total is 93.
  3. 22 — Split 11 by place value; multiply each part by 2 and add. Total is 22.
  4. 33 — Split 11 by place value; multiply each part by 3 and add. Total is 33.

Independent

  1. 222 — Split 111 by place value; multiply each part by 2 and add. Total is 222.
  2. 336 — Split 112 by place value; multiply each part by 3 and add. Total is 336.
  3. 244 — Split 122 by place value; multiply each part by 2 and add. Total is 244.
  4. 366 — Split 122 by place value; multiply each part by 3 and add. Total is 366.
  5. 464 — Split 232 by place value; multiply each part by 2 and add. Total is 464.
  6. 696 — Split 232 by place value; multiply each part by 3 and add. Total is 696.
  7. 424 — Split 212 by place value; multiply each part by 2 and add. Total is 424.
  8. 636 — Split 212 by place value; multiply each part by 3 and add. Total is 636.

Challenge

  1. The 2 represents 20 — 3×20=60 and 3×3=9, so the product is 69.
  2. 3 — 32×3 = (30×3)+(2×3)=90+6=96; both components do not require regrouping.

Exit

  1. 66 — Split 33 by place value; multiply each part by 2 and add. Total is 66.
  2. 99 — Split 33 by place value; multiply each part by 3 and add. Total is 99.
  3. 26 — Split 13 by place value; multiply each part by 2 and add. Total is 26.

Lesson 3: Multiplication with Regrouping Tens

Entry

  1. 646 — Split 323 by place value; multiply each part by 2 and add. Total is 646.
  2. 963 — Split 321 by place value; multiply each part by 3 and add. Total is 963.

Worked checks

  1. 213 — 71×3 = 0 + 210 + 3 = 213; combine partial products and exchange groups of ten.
  2. 243 — 81×3 = 0 + 240 + 3 = 243; combine partial products and exchange groups of ten.
  3. 273 — 91×3 = 0 + 270 + 3 = 273; combine partial products and exchange groups of ten.

Guided

  1. 153 — 51×3 = 0 + 150 + 3 = 153; combine partial products and exchange groups of ten.
  2. 183 — 61×3 = 0 + 180 + 3 = 183; combine partial products and exchange groups of ten.
  3. 142 — 71×2 = 0 + 140 + 2 = 142; combine partial products and exchange groups of ten.
  4. 162 — 81×2 = 0 + 160 + 2 = 162; combine partial products and exchange groups of ten.

Independent

  1. 156 — 52×3 = 0 + 150 + 6 = 156; combine partial products and exchange groups of ten.
  2. 186 — 62×3 = 0 + 180 + 6 = 186; combine partial products and exchange groups of ten.
  3. 216 — 72×3 = 0 + 210 + 6 = 216; combine partial products and exchange groups of ten.
  4. 246 — 82×3 = 0 + 240 + 6 = 246; combine partial products and exchange groups of ten.
  5. 276 — 92×3 = 0 + 270 + 6 = 276; combine partial products and exchange groups of ten.
  6. 159 — 53×3 = 0 + 150 + 9 = 159; combine partial products and exchange groups of ten.
  7. 189 — 63×3 = 0 + 180 + 9 = 189; combine partial products and exchange groups of ten.
  8. 219 — 73×3 = 0 + 210 + 9 = 219; combine partial products and exchange groups of ten.

Challenge

  1. 2 hundreds and 1 ten — 7×3=21 tens = 2 hundreds + 1 ten.
  2. 192 — 6 tens×3=18 tens, plus ones product 4×3=12 ones=1 ten+2 ones. Total 19 tens and 2 ones: 192; each position holds a single digit.

Exit

  1. 102 — 51×2 = 0 + 100 + 2 = 102; combine partial products and exchange groups of ten.
  2. 122 — 61×2 = 0 + 120 + 2 = 122; combine partial products and exchange groups of ten.
  3. 243 — 81×3 = 0 + 240 + 3 = 243; combine partial products and exchange groups of ten.

Lesson 4: Multiplication with Regrouping Ones

Entry

  1. 624 — Split 312 by place value; multiply each part by 2 and add. Total is 624.
  2. 936 — Split 312 by place value; multiply each part by 3 and add. Total is 936.

Worked checks

  1. 54 — 27×2 = 0 + 40 + 14 = 54; combine partial products and exchange groups of ten.
  2. 74 — 37×2 = 0 + 60 + 14 = 74; combine partial products and exchange groups of ten.
  3. 94 — 47×2 = 0 + 80 + 14 = 94; combine partial products and exchange groups of ten.

Guided

  1. 74 — 37×2 = 0 + 60 + 14 = 74; combine partial products and exchange groups of ten.
  2. 94 — 47×2 = 0 + 80 + 14 = 94; combine partial products and exchange groups of ten.
  3. 36 — 18×2 = 0 + 20 + 16 = 36; combine partial products and exchange groups of ten.
  4. 56 — 28×2 = 0 + 40 + 16 = 56; combine partial products and exchange groups of ten.

Independent

  1. 76 — 38×2 = 0 + 60 + 16 = 76; combine partial products and exchange groups of ten.
  2. 96 — 48×2 = 0 + 80 + 16 = 96; combine partial products and exchange groups of ten.
  3. 38 — 19×2 = 0 + 20 + 18 = 38; combine partial products and exchange groups of ten.
  4. 58 — 29×2 = 0 + 40 + 18 = 58; combine partial products and exchange groups of ten.
  5. 78 — 39×2 = 0 + 60 + 18 = 78; combine partial products and exchange groups of ten.
  6. 98 — 49×2 = 0 + 80 + 18 = 98; combine partial products and exchange groups of ten.
  7. 30 — 15×2 = 0 + 20 + 10 = 30; combine partial products and exchange groups of ten.
  8. 50 — 25×2 = 0 + 40 + 10 = 50; combine partial products and exchange groups of ten.

Challenge

  1. 2 tens — 8×3=24 ones = 2 tens and 4 ones.
  2. 81 — 7×3=21 ones=2 tens+1 one. The tens are 2×3 tens plus 2 carried tens =8 tens. Answer 81.

Exit

  1. 70 — 35×2 = 0 + 60 + 10 = 70; combine partial products and exchange groups of ten.
  2. 90 — 45×2 = 0 + 80 + 10 = 90; combine partial products and exchange groups of ten.
  3. 32 — 16×2 = 0 + 20 + 12 = 32; combine partial products and exchange groups of ten.

Lesson 5: Multiplication with Regrouping Ones and Tens

Entry

  1. 30 — 15×2 = 0 + 20 + 10 = 30; combine partial products and exchange groups of ten.
  2. 50 — 25×2 = 0 + 40 + 10 = 50; combine partial products and exchange groups of ten.

Worked checks

  1. 201 — 67×3 = 0 + 180 + 21 = 201; combine partial products and exchange groups of ten.
  2. 231 — 77×3 = 0 + 210 + 21 = 231; combine partial products and exchange groups of ten.
  3. 261 — 87×3 = 0 + 240 + 21 = 261; combine partial products and exchange groups of ten.

Guided

  1. 165 — 55×3 = 0 + 150 + 15 = 165; combine partial products and exchange groups of ten.
  2. 195 — 65×3 = 0 + 180 + 15 = 195; combine partial products and exchange groups of ten.
  3. 225 — 75×3 = 0 + 210 + 15 = 225; combine partial products and exchange groups of ten.
  4. 255 — 85×3 = 0 + 240 + 15 = 255; combine partial products and exchange groups of ten.

Independent

  1. 285 — 95×3 = 0 + 270 + 15 = 285; combine partial products and exchange groups of ten.
  2. 168 — 56×3 = 0 + 150 + 18 = 168; combine partial products and exchange groups of ten.
  3. 198 — 66×3 = 0 + 180 + 18 = 198; combine partial products and exchange groups of ten.
  4. 228 — 76×3 = 0 + 210 + 18 = 228; combine partial products and exchange groups of ten.
  5. 258 — 86×3 = 0 + 240 + 18 = 258; combine partial products and exchange groups of ten.
  6. 288 — 96×3 = 0 + 270 + 18 = 288; combine partial products and exchange groups of ten.
  7. 171 — 57×3 = 0 + 150 + 21 = 171; combine partial products and exchange groups of ten.
  8. 201 — 67×3 = 0 + 180 + 21 = 201; combine partial products and exchange groups of ten.

Challenge

  1. 312 — 70×4=280 and 8×4=32. Together 312; 32 ones create 3 tens, and 31 tens create 3 hundreds plus 1 ten.
  2. 276 — 9×4=36 ones=3 tens+6 ones. Then 6×4 tens +3 tens=27 tens=2 hundreds+7 tens. Product 276.

Exit

  1. 231 — 77×3 = 0 + 210 + 21 = 231; combine partial products and exchange groups of ten.
  2. 261 — 87×3 = 0 + 240 + 21 = 261; combine partial products and exchange groups of ten.
  3. 291 — 97×3 = 0 + 270 + 21 = 291; combine partial products and exchange groups of ten.

Lesson 6: Multiply a 3-digit Number with Regrouping Once

Entry

  1. 74 — 37×2 = 0 + 60 + 14 = 74; combine partial products and exchange groups of ten.
  2. 94 — 47×2 = 0 + 80 + 14 = 94; combine partial products and exchange groups of ten.

Worked checks

  1. 654 — 327×2 = 600 + 40 + 14 = 654; combine partial products and exchange groups of ten.
  2. 274 — 137×2 = 200 + 60 + 14 = 274; combine partial products and exchange groups of ten.
  3. 474 — 237×2 = 400 + 60 + 14 = 474; combine partial products and exchange groups of ten.

Guided

  1. 256 — 128×2 = 200 + 40 + 16 = 256; combine partial products and exchange groups of ten.
  2. 456 — 228×2 = 400 + 40 + 16 = 456; combine partial products and exchange groups of ten.
  3. 656 — 328×2 = 600 + 40 + 16 = 656; combine partial products and exchange groups of ten.
  4. 276 — 138×2 = 200 + 60 + 16 = 276; combine partial products and exchange groups of ten.

Independent

  1. 650 — 325×2 = 600 + 40 + 10 = 650; combine partial products and exchange groups of ten.
  2. 270 — 135×2 = 200 + 60 + 10 = 270; combine partial products and exchange groups of ten.
  3. 470 — 235×2 = 400 + 60 + 10 = 470; combine partial products and exchange groups of ten.
  4. 670 — 335×2 = 600 + 60 + 10 = 670; combine partial products and exchange groups of ten.
  5. 232 — 116×2 = 200 + 20 + 12 = 232; combine partial products and exchange groups of ten.
  6. 432 — 216×2 = 400 + 20 + 12 = 432; combine partial products and exchange groups of ten.
  7. 632 — 316×2 = 600 + 20 + 12 = 632; combine partial products and exchange groups of ten.
  8. 252 — 126×2 = 200 + 40 + 12 = 252; combine partial products and exchange groups of ten.

Challenge

  1. 252 — 2×6=12 ones, exchange into 1 ten and 2 ones; 2×2 tens plus carried 1 gives 5 tens; 2×1 hundred gives 2 hundreds.
  2. 272; ones — 6×2=12 ones=1 ten+2 ones. Three tens×2 plus the carried ten gives 7 tens; 1 hundred×2 gives 2 hundreds. Product 272.

Exit

  1. 230 — 115×2 = 200 + 20 + 10 = 230; combine partial products and exchange groups of ten.
  2. 430 — 215×2 = 400 + 20 + 10 = 430; combine partial products and exchange groups of ten.
  3. 630 — 315×2 = 600 + 20 + 10 = 630; combine partial products and exchange groups of ten.

Lesson 7: Multiplication with Regrouping More Than Once

Entry

  1. 272 — 136×2 = 200 + 60 + 12 = 272; combine partial products and exchange groups of ten.
  2. 472 — 236×2 = 400 + 60 + 12 = 472; combine partial products and exchange groups of ten.

Worked checks

  1. 1137 — 379×3 = 900 + 210 + 27 = 1137; combine partial products and exchange groups of ten.
  2. 1437 — 479×3 = 1200 + 210 + 27 = 1437; combine partial products and exchange groups of ten.
  3. 567 — 189×3 = 300 + 240 + 27 = 567; combine partial products and exchange groups of ten.

Guided

  1. 1137 — 379×3 = 900 + 210 + 27 = 1137; combine partial products and exchange groups of ten.
  2. 1437 — 479×3 = 1200 + 210 + 27 = 1437; combine partial products and exchange groups of ten.
  3. 567 — 189×3 = 300 + 240 + 27 = 567; combine partial products and exchange groups of ten.
  4. 867 — 289×3 = 600 + 240 + 27 = 867; combine partial products and exchange groups of ten.

Independent

  1. 1167 — 389×3 = 900 + 240 + 27 = 1167; combine partial products and exchange groups of ten.
  2. 1467 — 489×3 = 1200 + 240 + 27 = 1467; combine partial products and exchange groups of ten.
  3. 597 — 199×3 = 300 + 270 + 27 = 597; combine partial products and exchange groups of ten.
  4. 897 — 299×3 = 600 + 270 + 27 = 897; combine partial products and exchange groups of ten.
  5. 1197 — 399×3 = 900 + 270 + 27 = 1197; combine partial products and exchange groups of ten.
  6. 1497 — 499×3 = 1200 + 270 + 27 = 1497; combine partial products and exchange groups of ten.
  7. 465 — 155×3 = 300 + 150 + 15 = 465; combine partial products and exchange groups of ten.
  8. 765 — 255×3 = 600 + 150 + 15 = 765; combine partial products and exchange groups of ten.

Challenge

  1. 1,112 — 200×4 +70×4 +8×4 = 800+280+32 =1,112.
  2. 1,144 — 6×4=24 gives 2 carried tens; 8 tens×4+2=34 tens gives 3 carried hundreds; 2 hundreds×4+3=11 hundreds; answer 1,144.

Exit

  1. 1065 — 355×3 = 900 + 150 + 15 = 1065; combine partial products and exchange groups of ten.
  2. 1365 — 455×3 = 1200 + 150 + 15 = 1365; combine partial products and exchange groups of ten.
  3. 495 — 165×3 = 300 + 180 + 15 = 495; combine partial products and exchange groups of ten.

Practice A

Solutions

  1. 1400 — 200 is 2 groups of 100; 7×2=14 groups of 100 equals 1,400.
  2. 400 — 50 is 5 groups of 10; 8×5=40 groups of 10 equals 400.
  3. 1600 — 800 is 8 groups of 100; 2×8=16 groups of 100 equals 1,600.
  4. 644 — Split 322 by place value; multiply each part by 2 and add. Total is 644.
  5. 966 — Split 322 by place value; multiply each part by 3 and add. Total is 966.
  6. 664 — Split 332 by place value; multiply each part by 2 and add. Total is 664.
  7. 106 — 53×2 = 0 + 100 + 6 = 106; combine partial products and exchange groups of ten.
  8. 126 — 63×2 = 0 + 120 + 6 = 126; combine partial products and exchange groups of ten.
  9. 146 — 73×2 = 0 + 140 + 6 = 146; combine partial products and exchange groups of ten.
  10. 30 — 15×2 = 0 + 20 + 10 = 30; combine partial products and exchange groups of ten.
  11. 50 — 25×2 = 0 + 40 + 10 = 50; combine partial products and exchange groups of ten.
  12. 70 — 35×2 = 0 + 60 + 10 = 70; combine partial products and exchange groups of ten.

Practice B

Solutions

  1. 30 — 15×2 = 0 + 20 + 10 = 30; combine partial products and exchange groups of ten.
  2. 50 — 25×2 = 0 + 40 + 10 = 50; combine partial products and exchange groups of ten.
  3. 70 — 35×2 = 0 + 60 + 10 = 70; combine partial products and exchange groups of ten.
  4. 165 — 55×3 = 0 + 150 + 15 = 165; combine partial products and exchange groups of ten.
  5. 195 — 65×3 = 0 + 180 + 15 = 195; combine partial products and exchange groups of ten.
  6. 225 — 75×3 = 0 + 210 + 15 = 225; combine partial products and exchange groups of ten.
  7. 432 — 216×2 = 400 + 20 + 12 = 432; combine partial products and exchange groups of ten.
  8. 632 — 316×2 = 600 + 20 + 12 = 632; combine partial products and exchange groups of ten.
  9. 252 — 126×2 = 200 + 40 + 12 = 252; combine partial products and exchange groups of ten.
  10. 471 — 157×3 = 300 + 150 + 21 = 471; combine partial products and exchange groups of ten.
  11. 771 — 257×3 = 600 + 150 + 21 = 771; combine partial products and exchange groups of ten.
  12. 1071 — 357×3 = 900 + 150 + 21 = 1071; combine partial products and exchange groups of ten.

Chapter Review

Solutions

  1. 90 — 45×2 = 0 + 80 + 10 = 90; combine partial products and exchange groups of ten.
  2. 254 — 127×2 = 200 + 40 + 14 = 254; combine partial products and exchange groups of ten.
  3. 165 — 55×3 = 0 + 150 + 15 = 165; combine partial products and exchange groups of ten.
  4. 140 — 20 is 2 groups of 10; 7×2=14 groups of 10 equals 140.
  5. 694 — 7×2=14 ones (carry 1 ten); 4×2+1=9 tens; 3×2=6 hundreds.
  6. 70 — 35×2 = 0 + 60 + 10 = 70; combine partial products and exchange groups of ten.
  7. 246 — 82×3 = 0 + 240 + 6 = 246; combine partial products and exchange groups of ten.
  8. 963 — Split 321 by place value; multiply each part by 3 and add. Total is 963.
  9. 30 — 15×2 = 0 + 20 + 10 = 30; combine partial products and exchange groups of ten.
  10. 4000 — 500 is 5 groups of 100; 8×5=40 groups of 100 equals 4,000.
  11. 225 — 75×3 = 0 + 210 + 15 = 225; combine partial products and exchange groups of ten.
  12. 255 — 85×3 = 0 + 240 + 15 = 255; combine partial products and exchange groups of ten.
  13. 156 — 52×3 = 0 + 150 + 6 = 156; combine partial products and exchange groups of ten.
  14. 855 — 285×3 = 600 + 240 + 15 = 855; combine partial products and exchange groups of ten.
  15. 454 — 227×2 = 400 + 40 + 14 = 454; combine partial products and exchange groups of ten.
  16. 186 — 62×3 = 0 + 180 + 6 = 186; combine partial products and exchange groups of ten.
  17. 555 — 185×3 = 300 + 240 + 15 = 555; combine partial products and exchange groups of ten.
  18. 1425 — 475×3 = 1200 + 210 + 15 = 1425; combine partial products and exchange groups of ten.
  19. 446 — Split 223 by place value; multiply each part by 2 and add. Total is 446.
  20. 761 — 4×186=744, plus 17 unpacked makes 761.
  21. 160 — 80 is 8 groups of 10; 2×8=16 groups of 10 equals 160.
  22. 634 — 317×2 = 600 + 20 + 14 = 634; combine partial products and exchange groups of ten.
  23. 4800 — 800 is 8 groups of 100; 6×8=48 groups of 100 equals 4,800.
  24. 654 — 327×2 = 600 + 40 + 14 = 654; combine partial products and exchange groups of ten.
  25. 662 — Split 331 by place value; multiply each part by 2 and add. Total is 662.
  26. 258 — 80×3=240 and 6×3=18; add 240+18=258, not concatenate them.
  27. Two hundreds is 200 — 9×2 hundreds=18 hundreds=1,800 ones.
  28. 1125 — 375×3 = 900 + 210 + 15 = 1125; combine partial products and exchange groups of ten.
  29. 195 — 65×3 = 0 + 180 + 15 = 195; combine partial products and exchange groups of ten.
  30. 50 — 25×2 = 0 + 40 + 10 = 50; combine partial products and exchange groups of ten.
  31. 216 — 72×3 = 0 + 210 + 6 = 216; combine partial products and exchange groups of ten.
  32. 993 — Split 331 by place value; multiply each part by 3 and add. Total is 993.

Practice Exam

Solutions

  1. Distributive property — 26 is 20+6. Four copies of the whole contain four copies of both parts.
  2. 336 — Split 112 by place value; multiply each part by 3 and add. Total is 336.
  3. 31×4 by 6 — 59×2=118 and 31×4=124, difference 6.
  4. 114 — 30×3=90, 8×3=24. Add 90+24=114; partial products must be added using place values.
  5. 790 — 6×135=810; 810−20=790.
  6. 222 — 4×3=12 ones=1 ten+2 ones; 7 tens×3+1=22 tens=2 hundreds+2 tens.
  7. 1425 — 475×3 = 1200 + 210 + 15 = 1425; combine partial products and exchange groups of ten.
  8. 30 — 15×2 = 0 + 20 + 10 = 30; combine partial products and exchange groups of ten.
  9. 400 — 200 is 2 groups of 100; 2×2=4 groups of 100 equals 400.
  10. 621 — 200×3=600 and 7×3=21. Zero tens is a placeholder, product 621.
  11. Forty is four tens — 6×4 tens =24 tens=240 ones.
  12. 50 — 25×2 = 0 + 40 + 10 = 50; combine partial products and exchange groups of ten.
  13. 472 — 236×2 = 400 + 60 + 12 = 472; combine partial products and exchange groups of ten.
  14. 122 — 61×2 = 0 + 120 + 2 = 122; combine partial products and exchange groups of ten.
  15. 204 — 8×3=24 ones gives 2 extra tens; 6 tens×3+2 tens=20 tens. So product is 204.
  16. 552 — 184×3=552.
  17. 195 — 65×3 = 0 + 180 + 15 = 195; combine partial products and exchange groups of ten.
  18. 102 — 51×2 = 0 + 100 + 2 = 102; combine partial products and exchange groups of ten.
  19. 165 — 55×3 = 0 + 150 + 15 = 165; combine partial products and exchange groups of ten.
  20. 224 — Split 112 by place value; multiply each part by 2 and add. Total is 224.
  21. 1125 — 375×3 = 900 + 210 + 15 = 1125; combine partial products and exchange groups of ten.
  22. 272 — 136×2 = 200 + 60 + 12 = 272; combine partial products and exchange groups of ten.
  23. 150 — 50 is 5 groups of 10; 3×5=15 groups of 10 equals 150.
  24. 504 — 4×(100+20+6)=400+80+24=504.