Let's roll up our sleeves and solve this. We have 35 and we're going to multiply it by 72, essentially adding 35 to itself 72 times.
Step 1: 0 + 35 = 35
Step 2: 35 + 35 = 70
Step 3: 70 + 35 = 105
Step 4: 105 + 35 = 140
Step 5: 140 + 35 = 175
Step 6: 175 + 35 = 210
Step 7: 210 + 35 = 245
Step 8: 245 + 35 = 280
Step 9: 280 + 35 = 315
Step 10: 315 + 35 = 350
Step 11: 350 + 35 = 385
Step 12: 385 + 35 = 420
Step 13: 420 + 35 = 455
Step 14: 455 + 35 = 490
Step 15: 490 + 35 = 525
Step 16: 525 + 35 = 560
Step 17: 560 + 35 = 595
Step 18: 595 + 35 = 630
Step 19: 630 + 35 = 665
Step 20: 665 + 35 = 700
Step 21: 700 + 35 = 735
Step 22: 735 + 35 = 770
Step 23: 770 + 35 = 805
Step 24: 805 + 35 = 840
Step 25: 840 + 35 = 875
Step 26: 875 + 35 = 910
Step 27: 910 + 35 = 945
Step 28: 945 + 35 = 980
Step 29: 980 + 35 = 1015
Step 30: 1015 + 35 = 1050
Step 31: 1050 + 35 = 1085
Step 32: 1085 + 35 = 1120
Step 33: 1120 + 35 = 1155
Step 34: 1155 + 35 = 1190
Step 35: 1190 + 35 = 1225
Step 36: 1225 + 35 = 1260
Step 37: 1260 + 35 = 1295
Step 38: 1295 + 35 = 1330
Step 39: 1330 + 35 = 1365
Step 40: 1365 + 35 = 1400
Step 41: 1400 + 35 = 1435
Step 42: 1435 + 35 = 1470
Step 43: 1470 + 35 = 1505
Step 44: 1505 + 35 = 1540
Step 45: 1540 + 35 = 1575
Step 46: 1575 + 35 = 1610
Step 47: 1610 + 35 = 1645
Step 48: 1645 + 35 = 1680
Step 49: 1680 + 35 = 1715
Step 50: 1715 + 35 = 1750
Step 51: 1750 + 35 = 1785
Step 52: 1785 + 35 = 1820
Step 53: 1820 + 35 = 1855
Step 54: 1855 + 35 = 1890
Step 55: 1890 + 35 = 1925
Step 56: 1925 + 35 = 1960
Step 57: 1960 + 35 = 1995
Step 58: 1995 + 35 = 2030
Step 59: 2030 + 35 = 2065
Step 60: 2065 + 35 = 2100
Step 61: 2100 + 35 = 2135
Step 62: 2135 + 35 = 2170
Step 63: 2170 + 35 = 2205
Step 64: 2205 + 35 = 2240
Step 65: 2240 + 35 = 2275
Step 66: 2275 + 35 = 2310
Step 67: 2310 + 35 = 2345
Step 68: 2345 + 35 = 2380
Step 69: 2380 + 35 = 2415
Step 70: 2415 + 35 = 2450
Step 71: 2450 + 35 = 2485
Step 72: 2485 + 35 = 2520

So, 35*72 = 2520