Sure thing! We've got 105 and we're gonna multiply it by 31. That's the same as adding 105 to itself 31 times.
Step 1: 0 + 105 = 105
Step 2: 105 + 105 = 210
Step 3: 210 + 105 = 315
Step 4: 315 + 105 = 420
Step 5: 420 + 105 = 525
Step 6: 525 + 105 = 630
Step 7: 630 + 105 = 735
Step 8: 735 + 105 = 840
Step 9: 840 + 105 = 945
Step 10: 945 + 105 = 1050
Step 11: 1050 + 105 = 1155
Step 12: 1155 + 105 = 1260
Step 13: 1260 + 105 = 1365
Step 14: 1365 + 105 = 1470
Step 15: 1470 + 105 = 1575
Step 16: 1575 + 105 = 1680
Step 17: 1680 + 105 = 1785
Step 18: 1785 + 105 = 1890
Step 19: 1890 + 105 = 1995
Step 20: 1995 + 105 = 2100
Step 21: 2100 + 105 = 2205
Step 22: 2205 + 105 = 2310
Step 23: 2310 + 105 = 2415
Step 24: 2415 + 105 = 2520
Step 25: 2520 + 105 = 2625
Step 26: 2625 + 105 = 2730
Step 27: 2730 + 105 = 2835
Step 28: 2835 + 105 = 2940
Step 29: 2940 + 105 = 3045
Step 30: 3045 + 105 = 3150
Step 31: 3150 + 105 = 3255

So, 105*31 = 3255