Multiply Two Digit 80B621

1. The problem is to multiply two-digit numbers by one-digit numbers. 2. The general formula for multiplication is: $$a \times b = c$$ where $a$ and $b$ are numbers and $c$ is the product. 3. Let's solve the first problem: $23 \times 5$. 4. Multiply the units digit: $3 \times 5 = 15$. Write down 5 and carry over 1. 5. Multiply the tens digit: $2 \times 5 = 10$. Add the carry over: $10 + 1 = 11$. 6. So, $23 \times 5 = 115$. 7. Next, $43 \times 7$: 8. Units: $3 \times 7 = 21$. Write 1, carry 2. 9. Tens: $4 \times 7 = 28$. Add carry: $28 + 2 = 30$. 10. Result: $43 \times 7 = 301$. 11. Next, $38 \times 8$: 12. Units: $8 \times 8 = 64$. Write 4, carry 6. 13. Tens: $3 \times 8 = 24$. Add carry: $24 + 6 = 30$. 14. Result: $38 \times 8 = 304$. 15. Next, $84 \times 9$: 16. Units: $4 \times 9 = 36$. Write 6, carry 3. 17. Tens: $8 \times 9 = 72$. Add carry: $72 + 3 = 75$. 18. Result: $84 \times 9 = 756$. 19. Next, $99 \times 9$: 20. Units: $9 \times 9 = 81$. Write 1, carry 8. 21. Tens: $9 \times 9 = 81$. Add carry: $81 + 8 = 89$. 22. Result: $99 \times 9 = 891$. 23. Next, $34 \times 7$: 24. Units: $4 \times 7 = 28$. Write 8, carry 2. 25. Tens: $3 \times 7 = 21$. Add carry: $21 + 2 = 23$. 26. Result: $34 \times 7 = 238$. 27. Next, $43 \times 9$: 28. Units: $3 \times 9 = 27$. Write 7, carry 2. 29. Tens: $4 \times 9 = 36$. Add carry: $36 + 2 = 38$. 30. Result: $43 \times 9 = 387$. 31. Next, $54 \times 8$: 32. Units: $4 \times 8 = 32$. Write 2, carry 3. 33. Tens: $5 \times 8 = 40$. Add carry: $40 + 3 = 43$. 34. Result: $54 \times 8 = 432$. 35. Next, $79 \times 8$: 36. Units: $9 \times 8 = 72$. Write 2, carry 7. 37. Tens: $7 \times 8 = 56$. Add carry: $56 + 7 = 63$. 38. Result: $79 \times 8 = 632$. 39. Next, $76 \times 7$: 40. Units: $6 \times 7 = 42$. Write 2, carry 4. 41. Tens: $7 \times 7 = 49$. Add carry: $49 + 4 = 53$. 42. Result: $76 \times 7 = 532$. 43. Next, $89 \times 4$: 44. Units: $9 \times 4 = 36$. Write 6, carry 3. 45. Tens: $8 \times 4 = 32$. Add carry: $32 + 3 = 35$. 46. Result: $89 \times 4 = 356$. 47. Next, $71 \times 8$: 48. Units: $1 \times 8 = 8$. Write 8. 49. Tens: $7 \times 8 = 56$. 50. Result: $71 \times 8 = 568$. 51. Next, $83 \times 5$: 52. Units: $3 \times 5 = 15$. Write 5, carry 1. 53. Tens: $8 \times 5 = 40$. Add carry: $40 + 1 = 41$. 54. Result: $83 \times 5 = 415$. 55. Next, $75 \times 6$: 56. Units: $5 \times 6 = 30$. Write 0, carry 3. 57. Tens: $7 \times 6 = 42$. Add carry: $42 + 3 = 45$. 58. Result: $75 \times 6 = 450$. 59. Next, $36 \times 9$: 60. Units: $6 \times 9 = 54$. Write 4, carry 5. 61. Tens: $3 \times 9 = 27$. Add carry: $27 + 5 = 32$. 62. Result: $36 \times 9 = 324$. 63. Next, $64 \times 8$: 64. Units: $4 \times 8 = 32$. Write 2, carry 3. 65. Tens: $6 \times 8 = 48$. Add carry: $48 + 3 = 51$. 66. Result: $64 \times 8 = 512$. 67. Next, $19 \times 9$: 68. Units: $9 \times 9 = 81$. Write 1, carry 8. 69. Tens: $1 \times 9 = 9$. Add carry: $9 + 8 = 17$. 70. Result: $19 \times 9 = 171$. 71. Next, $57 \times 2$: 72. Units: $7 \times 2 = 14$. Write 4, carry 1. 73. Tens: $5 \times 2 = 10$. Add carry: $10 + 1 = 11$. 74. Result: $57 \times 2 = 114$. 75. Next, $93 \times 9$: 76. Units: $3 \times 9 = 27$. Write 7, carry 2. 77. Tens: $9 \times 9 = 81$. Add carry: $81 + 2 = 83$. 78. Result: $93 \times 9 = 837$. 79. Next, $77 \times 8$: 80. Units: $7 \times 8 = 56$. Write 6, carry 5. 81. Tens: $7 \times 8 = 56$. Add carry: $56 + 5 = 61$. 82. Result: $77 \times 8 = 616$. 83. Next, $58 \times 8$: 84. Units: $8 \times 8 = 64$. Write 4, carry 6. 85. Tens: $5 \times 8 = 40$. Add carry: $40 + 6 = 46$. 86. Result: $58 \times 8 = 464$. 87. Next, $39 \times 7$: 88. Units: $9 \times 7 = 63$. Write 3, carry 6. 89. Tens: $3 \times 7 = 21$. Add carry: $21 + 6 = 27$. 90. Result: $39 \times 7 = 273$. 91. Next, $26 \times 6$: 92. Units: $6 \times 6 = 36$. Write 6, carry 3. 93. Tens: $2 \times 6 = 12$. Add carry: $12 + 3 = 15$. 94. Result: $26 \times 6 = 156$. 95. Next, $68 \times 3$: 96. Units: $8 \times 3 = 24$. Write 4, carry 2. 97. Tens: $6 \times 3 = 18$. Add carry: $18 + 2 = 20$. 98. Result: $68 \times 3 = 204$. Final answer for the first problem $23 \times 5$ is $115$.