Let's get this math done. We have 778 and we're going to multiply it by 31. This is the same as taking 778 and adding it to itself 31 times.
Step 1: 0 + 778 = 778
Step 2: 778 + 778 = 1556
Step 3: 1556 + 778 = 2334
Step 4: 2334 + 778 = 3112
Step 5: 3112 + 778 = 3890
Step 6: 3890 + 778 = 4668
Step 7: 4668 + 778 = 5446
Step 8: 5446 + 778 = 6224
Step 9: 6224 + 778 = 7002
Step 10: 7002 + 778 = 7780
Step 11: 7780 + 778 = 8558
Step 12: 8558 + 778 = 9336
Step 13: 9336 + 778 = 10114
Step 14: 10114 + 778 = 10892
Step 15: 10892 + 778 = 11670
Step 16: 11670 + 778 = 12448
Step 17: 12448 + 778 = 13226
Step 18: 13226 + 778 = 14004
Step 19: 14004 + 778 = 14782
Step 20: 14782 + 778 = 15560
Step 21: 15560 + 778 = 16338
Step 22: 16338 + 778 = 17116
Step 23: 17116 + 778 = 17894
Step 24: 17894 + 778 = 18672
Step 25: 18672 + 778 = 19450
Step 26: 19450 + 778 = 20228
Step 27: 20228 + 778 = 21006
Step 28: 21006 + 778 = 21784
Step 29: 21784 + 778 = 22562
Step 30: 22562 + 778 = 23340
Step 31: 23340 + 778 = 24118

So, 778*31 = 24118