OK, let's work through this together. We're starting with 5 and we're going to multiply it by 124, which means we add 5 to itself 124 times.
Step 1: 0 + 5 = 5
Step 2: 5 + 5 = 10
Step 3: 10 + 5 = 15
Step 4: 15 + 5 = 20
Step 5: 20 + 5 = 25
Step 6: 25 + 5 = 30
Step 7: 30 + 5 = 35
Step 8: 35 + 5 = 40
Step 9: 40 + 5 = 45
Step 10: 45 + 5 = 50
Step 11: 50 + 5 = 55
Step 12: 55 + 5 = 60
Step 13: 60 + 5 = 65
Step 14: 65 + 5 = 70
Step 15: 70 + 5 = 75
Step 16: 75 + 5 = 80
Step 17: 80 + 5 = 85
Step 18: 85 + 5 = 90
Step 19: 90 + 5 = 95
Step 20: 95 + 5 = 100
Step 21: 100 + 5 = 105
Step 22: 105 + 5 = 110
Step 23: 110 + 5 = 115
Step 24: 115 + 5 = 120
Step 25: 120 + 5 = 125
Step 26: 125 + 5 = 130
Step 27: 130 + 5 = 135
Step 28: 135 + 5 = 140
Step 29: 140 + 5 = 145
Step 30: 145 + 5 = 150
Step 31: 150 + 5 = 155
Step 32: 155 + 5 = 160
Step 33: 160 + 5 = 165
Step 34: 165 + 5 = 170
Step 35: 170 + 5 = 175
Step 36: 175 + 5 = 180
Step 37: 180 + 5 = 185
Step 38: 185 + 5 = 190
Step 39: 190 + 5 = 195
Step 40: 195 + 5 = 200
Step 41: 200 + 5 = 205
Step 42: 205 + 5 = 210
Step 43: 210 + 5 = 215
Step 44: 215 + 5 = 220
Step 45: 220 + 5 = 225
Step 46: 225 + 5 = 230
Step 47: 230 + 5 = 235
Step 48: 235 + 5 = 240
Step 49: 240 + 5 = 245
Step 50: 245 + 5 = 250
Step 51: 250 + 5 = 255
Step 52: 255 + 5 = 260
Step 53: 260 + 5 = 265
Step 54: 265 + 5 = 270
Step 55: 270 + 5 = 275
Step 56: 275 + 5 = 280
Step 57: 280 + 5 = 285
Step 58: 285 + 5 = 290
Step 59: 290 + 5 = 295
Step 60: 295 + 5 = 300
Step 61: 300 + 5 = 305
Step 62: 305 + 5 = 310
Step 63: 310 + 5 = 315
Step 64: 315 + 5 = 320
Step 65: 320 + 5 = 325
Step 66: 325 + 5 = 330
Step 67: 330 + 5 = 335
Step 68: 335 + 5 = 340
Step 69: 340 + 5 = 345
Step 70: 345 + 5 = 350
Step 71: 350 + 5 = 355
Step 72: 355 + 5 = 360
Step 73: 360 + 5 = 365
Step 74: 365 + 5 = 370
Step 75: 370 + 5 = 375
Step 76: 375 + 5 = 380
Step 77: 380 + 5 = 385
Step 78: 385 + 5 = 390
Step 79: 390 + 5 = 395
Step 80: 395 + 5 = 400
Step 81: 400 + 5 = 405
Step 82: 405 + 5 = 410
Step 83: 410 + 5 = 415
Step 84: 415 + 5 = 420
Step 85: 420 + 5 = 425
Step 86: 425 + 5 = 430
Step 87: 430 + 5 = 435
Step 88: 435 + 5 = 440
Step 89: 440 + 5 = 445
Step 90: 445 + 5 = 450
Step 91: 450 + 5 = 455
Step 92: 455 + 5 = 460
Step 93: 460 + 5 = 465
Step 94: 465 + 5 = 470
Step 95: 470 + 5 = 475
Step 96: 475 + 5 = 480
Step 97: 480 + 5 = 485
Step 98: 485 + 5 = 490
Step 99: 490 + 5 = 495
Step 100: 495 + 5 = 500
Step 101: 500 + 5 = 505
Step 102: 505 + 5 = 510
Step 103: 510 + 5 = 515
Step 104: 515 + 5 = 520
Step 105: 520 + 5 = 525
Step 106: 525 + 5 = 530
Step 107: 530 + 5 = 535
Step 108: 535 + 5 = 540
Step 109: 540 + 5 = 545
Step 110: 545 + 5 = 550
Step 111: 550 + 5 = 555
Step 112: 555 + 5 = 560
Step 113: 560 + 5 = 565
Step 114: 565 + 5 = 570
Step 115: 570 + 5 = 575
Step 116: 575 + 5 = 580
Step 117: 580 + 5 = 585
Step 118: 585 + 5 = 590
Step 119: 590 + 5 = 595
Step 120: 595 + 5 = 600
Step 121: 600 + 5 = 605
Step 122: 605 + 5 = 610
Step 123: 610 + 5 = 615
Step 124: 615 + 5 = 620

So, 5*124 = 620