Alright, let's solve this math problem step by step. First, we have the number 51. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 78. So, we're going to take the number 51 and add it to itself 78 times.
Step 1: 0 + 51 = 51
Step 2: 51 + 51 = 102
Step 3: 102 + 51 = 153
Step 4: 153 + 51 = 204
Step 5: 204 + 51 = 255
Step 6: 255 + 51 = 306
Step 7: 306 + 51 = 357
Step 8: 357 + 51 = 408
Step 9: 408 + 51 = 459
Step 10: 459 + 51 = 510
Step 11: 510 + 51 = 561
Step 12: 561 + 51 = 612
Step 13: 612 + 51 = 663
Step 14: 663 + 51 = 714
Step 15: 714 + 51 = 765
Step 16: 765 + 51 = 816
Step 17: 816 + 51 = 867
Step 18: 867 + 51 = 918
Step 19: 918 + 51 = 969
Step 20: 969 + 51 = 1020
Step 21: 1020 + 51 = 1071
Step 22: 1071 + 51 = 1122
Step 23: 1122 + 51 = 1173
Step 24: 1173 + 51 = 1224
Step 25: 1224 + 51 = 1275
Step 26: 1275 + 51 = 1326
Step 27: 1326 + 51 = 1377
Step 28: 1377 + 51 = 1428
Step 29: 1428 + 51 = 1479
Step 30: 1479 + 51 = 1530
Step 31: 1530 + 51 = 1581
Step 32: 1581 + 51 = 1632
Step 33: 1632 + 51 = 1683
Step 34: 1683 + 51 = 1734
Step 35: 1734 + 51 = 1785
Step 36: 1785 + 51 = 1836
Step 37: 1836 + 51 = 1887
Step 38: 1887 + 51 = 1938
Step 39: 1938 + 51 = 1989
Step 40: 1989 + 51 = 2040
Step 41: 2040 + 51 = 2091
Step 42: 2091 + 51 = 2142
Step 43: 2142 + 51 = 2193
Step 44: 2193 + 51 = 2244
Step 45: 2244 + 51 = 2295
Step 46: 2295 + 51 = 2346
Step 47: 2346 + 51 = 2397
Step 48: 2397 + 51 = 2448
Step 49: 2448 + 51 = 2499
Step 50: 2499 + 51 = 2550
Step 51: 2550 + 51 = 2601
Step 52: 2601 + 51 = 2652
Step 53: 2652 + 51 = 2703
Step 54: 2703 + 51 = 2754
Step 55: 2754 + 51 = 2805
Step 56: 2805 + 51 = 2856
Step 57: 2856 + 51 = 2907
Step 58: 2907 + 51 = 2958
Step 59: 2958 + 51 = 3009
Step 60: 3009 + 51 = 3060
Step 61: 3060 + 51 = 3111
Step 62: 3111 + 51 = 3162
Step 63: 3162 + 51 = 3213
Step 64: 3213 + 51 = 3264
Step 65: 3264 + 51 = 3315
Step 66: 3315 + 51 = 3366
Step 67: 3366 + 51 = 3417
Step 68: 3417 + 51 = 3468
Step 69: 3468 + 51 = 3519
Step 70: 3519 + 51 = 3570
Step 71: 3570 + 51 = 3621
Step 72: 3621 + 51 = 3672
Step 73: 3672 + 51 = 3723
Step 74: 3723 + 51 = 3774
Step 75: 3774 + 51 = 3825
Step 76: 3825 + 51 = 3876
Step 77: 3876 + 51 = 3927
Step 78: 3927 + 51 = 3978

So, 51*78 = 3978