Let's roll up our sleeves and solve this. We have 139 and we're going to multiply it by 46, essentially adding 139 to itself 46 times.
Step 1: 0 + 139 = 139
Step 2: 139 + 139 = 278
Step 3: 278 + 139 = 417
Step 4: 417 + 139 = 556
Step 5: 556 + 139 = 695
Step 6: 695 + 139 = 834
Step 7: 834 + 139 = 973
Step 8: 973 + 139 = 1112
Step 9: 1112 + 139 = 1251
Step 10: 1251 + 139 = 1390
Step 11: 1390 + 139 = 1529
Step 12: 1529 + 139 = 1668
Step 13: 1668 + 139 = 1807
Step 14: 1807 + 139 = 1946
Step 15: 1946 + 139 = 2085
Step 16: 2085 + 139 = 2224
Step 17: 2224 + 139 = 2363
Step 18: 2363 + 139 = 2502
Step 19: 2502 + 139 = 2641
Step 20: 2641 + 139 = 2780
Step 21: 2780 + 139 = 2919
Step 22: 2919 + 139 = 3058
Step 23: 3058 + 139 = 3197
Step 24: 3197 + 139 = 3336
Step 25: 3336 + 139 = 3475
Step 26: 3475 + 139 = 3614
Step 27: 3614 + 139 = 3753
Step 28: 3753 + 139 = 3892
Step 29: 3892 + 139 = 4031
Step 30: 4031 + 139 = 4170
Step 31: 4170 + 139 = 4309
Step 32: 4309 + 139 = 4448
Step 33: 4448 + 139 = 4587
Step 34: 4587 + 139 = 4726
Step 35: 4726 + 139 = 4865
Step 36: 4865 + 139 = 5004
Step 37: 5004 + 139 = 5143
Step 38: 5143 + 139 = 5282
Step 39: 5282 + 139 = 5421
Step 40: 5421 + 139 = 5560
Step 41: 5560 + 139 = 5699
Step 42: 5699 + 139 = 5838
Step 43: 5838 + 139 = 5977
Step 44: 5977 + 139 = 6116
Step 45: 6116 + 139 = 6255
Step 46: 6255 + 139 = 6394

So, 139*46 = 6394