Alright, let's solve this math problem step by step. First, we have the number 378. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 13. So, we're going to take the number 378 and add it to itself 13 times.
Step 1: 0 + 378 = 378
Step 2: 378 + 378 = 756
Step 3: 756 + 378 = 1134
Step 4: 1134 + 378 = 1512
Step 5: 1512 + 378 = 1890
Step 6: 1890 + 378 = 2268
Step 7: 2268 + 378 = 2646
Step 8: 2646 + 378 = 3024
Step 9: 3024 + 378 = 3402
Step 10: 3402 + 378 = 3780
Step 11: 3780 + 378 = 4158
Step 12: 4158 + 378 = 4536
Step 13: 4536 + 378 = 4914

So, 378*13 = 4914