Alright, let's solve this math problem step by step. First, we have the number 816. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 23. So, we're going to take the number 816 and add it to itself 23 times.
Step 1: 0 + 816 = 816
Step 2: 816 + 816 = 1632
Step 3: 1632 + 816 = 2448
Step 4: 2448 + 816 = 3264
Step 5: 3264 + 816 = 4080
Step 6: 4080 + 816 = 4896
Step 7: 4896 + 816 = 5712
Step 8: 5712 + 816 = 6528
Step 9: 6528 + 816 = 7344
Step 10: 7344 + 816 = 8160
Step 11: 8160 + 816 = 8976
Step 12: 8976 + 816 = 9792
Step 13: 9792 + 816 = 10608
Step 14: 10608 + 816 = 11424
Step 15: 11424 + 816 = 12240
Step 16: 12240 + 816 = 13056
Step 17: 13056 + 816 = 13872
Step 18: 13872 + 816 = 14688
Step 19: 14688 + 816 = 15504
Step 20: 15504 + 816 = 16320
Step 21: 16320 + 816 = 17136
Step 22: 17136 + 816 = 17952
Step 23: 17952 + 816 = 18768

So, 816*23 = 18768