Alright, let's solve this math problem step by step. First, we have the number 368. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 21. So, we're going to take the number 368 and add it to itself 21 times.
Step 1: 0 + 368 = 368
Step 2: 368 + 368 = 736
Step 3: 736 + 368 = 1104
Step 4: 1104 + 368 = 1472
Step 5: 1472 + 368 = 1840
Step 6: 1840 + 368 = 2208
Step 7: 2208 + 368 = 2576
Step 8: 2576 + 368 = 2944
Step 9: 2944 + 368 = 3312
Step 10: 3312 + 368 = 3680
Step 11: 3680 + 368 = 4048
Step 12: 4048 + 368 = 4416
Step 13: 4416 + 368 = 4784
Step 14: 4784 + 368 = 5152
Step 15: 5152 + 368 = 5520
Step 16: 5520 + 368 = 5888
Step 17: 5888 + 368 = 6256
Step 18: 6256 + 368 = 6624
Step 19: 6624 + 368 = 6992
Step 20: 6992 + 368 = 7360
Step 21: 7360 + 368 = 7728

So, 368*21 = 7728