Alright, let's solve this math problem step by step. First, we have the number 159. 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 159 and add it to itself 78 times.
Step 1: 0 + 159 = 159
Step 2: 159 + 159 = 318
Step 3: 318 + 159 = 477
Step 4: 477 + 159 = 636
Step 5: 636 + 159 = 795
Step 6: 795 + 159 = 954
Step 7: 954 + 159 = 1113
Step 8: 1113 + 159 = 1272
Step 9: 1272 + 159 = 1431
Step 10: 1431 + 159 = 1590
Step 11: 1590 + 159 = 1749
Step 12: 1749 + 159 = 1908
Step 13: 1908 + 159 = 2067
Step 14: 2067 + 159 = 2226
Step 15: 2226 + 159 = 2385
Step 16: 2385 + 159 = 2544
Step 17: 2544 + 159 = 2703
Step 18: 2703 + 159 = 2862
Step 19: 2862 + 159 = 3021
Step 20: 3021 + 159 = 3180
Step 21: 3180 + 159 = 3339
Step 22: 3339 + 159 = 3498
Step 23: 3498 + 159 = 3657
Step 24: 3657 + 159 = 3816
Step 25: 3816 + 159 = 3975
Step 26: 3975 + 159 = 4134
Step 27: 4134 + 159 = 4293
Step 28: 4293 + 159 = 4452
Step 29: 4452 + 159 = 4611
Step 30: 4611 + 159 = 4770
Step 31: 4770 + 159 = 4929
Step 32: 4929 + 159 = 5088
Step 33: 5088 + 159 = 5247
Step 34: 5247 + 159 = 5406
Step 35: 5406 + 159 = 5565
Step 36: 5565 + 159 = 5724
Step 37: 5724 + 159 = 5883
Step 38: 5883 + 159 = 6042
Step 39: 6042 + 159 = 6201
Step 40: 6201 + 159 = 6360
Step 41: 6360 + 159 = 6519
Step 42: 6519 + 159 = 6678
Step 43: 6678 + 159 = 6837
Step 44: 6837 + 159 = 6996
Step 45: 6996 + 159 = 7155
Step 46: 7155 + 159 = 7314
Step 47: 7314 + 159 = 7473
Step 48: 7473 + 159 = 7632
Step 49: 7632 + 159 = 7791
Step 50: 7791 + 159 = 7950
Step 51: 7950 + 159 = 8109
Step 52: 8109 + 159 = 8268
Step 53: 8268 + 159 = 8427
Step 54: 8427 + 159 = 8586
Step 55: 8586 + 159 = 8745
Step 56: 8745 + 159 = 8904
Step 57: 8904 + 159 = 9063
Step 58: 9063 + 159 = 9222
Step 59: 9222 + 159 = 9381
Step 60: 9381 + 159 = 9540
Step 61: 9540 + 159 = 9699
Step 62: 9699 + 159 = 9858
Step 63: 9858 + 159 = 10017
Step 64: 10017 + 159 = 10176
Step 65: 10176 + 159 = 10335
Step 66: 10335 + 159 = 10494
Step 67: 10494 + 159 = 10653
Step 68: 10653 + 159 = 10812
Step 69: 10812 + 159 = 10971
Step 70: 10971 + 159 = 11130
Step 71: 11130 + 159 = 11289
Step 72: 11289 + 159 = 11448
Step 73: 11448 + 159 = 11607
Step 74: 11607 + 159 = 11766
Step 75: 11766 + 159 = 11925
Step 76: 11925 + 159 = 12084
Step 77: 12084 + 159 = 12243
Step 78: 12243 + 159 = 12402

So, 159*78 = 12402