OK, let's crack this. We're given 519 and our task is to multiply it by 23. Essentially, we'll be adding 519 to itself 23 times.
Step 1: 0 + 519 = 519
Step 2: 519 + 519 = 1038
Step 3: 1038 + 519 = 1557
Step 4: 1557 + 519 = 2076
Step 5: 2076 + 519 = 2595
Step 6: 2595 + 519 = 3114
Step 7: 3114 + 519 = 3633
Step 8: 3633 + 519 = 4152
Step 9: 4152 + 519 = 4671
Step 10: 4671 + 519 = 5190
Step 11: 5190 + 519 = 5709
Step 12: 5709 + 519 = 6228
Step 13: 6228 + 519 = 6747
Step 14: 6747 + 519 = 7266
Step 15: 7266 + 519 = 7785
Step 16: 7785 + 519 = 8304
Step 17: 8304 + 519 = 8823
Step 18: 8823 + 519 = 9342
Step 19: 9342 + 519 = 9861
Step 20: 9861 + 519 = 10380
Step 21: 10380 + 519 = 10899
Step 22: 10899 + 519 = 11418
Step 23: 11418 + 519 = 11937

So, 519*23 = 11937