Alright, let's solve this math problem step by step. First, we have the number 723. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 15. So, we're going to take the number 723 and add it to itself 15 times.
Step 1: 0 + 723 = 723
Step 2: 723 + 723 = 1446
Step 3: 1446 + 723 = 2169
Step 4: 2169 + 723 = 2892
Step 5: 2892 + 723 = 3615
Step 6: 3615 + 723 = 4338
Step 7: 4338 + 723 = 5061
Step 8: 5061 + 723 = 5784
Step 9: 5784 + 723 = 6507
Step 10: 6507 + 723 = 7230
Step 11: 7230 + 723 = 7953
Step 12: 7953 + 723 = 8676
Step 13: 8676 + 723 = 9399
Step 14: 9399 + 723 = 10122
Step 15: 10122 + 723 = 10845

So, 723*15 = 10845