Alright, let's solve this math problem step by step. First, we have the number 390. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 3. So, we're going to take the number 390 and add it to itself 3 times.
Step 1: 0 + 390 = 390
Step 2: 390 + 390 = 780
Step 3: 780 + 390 = 1170

So, 390*3 = 1170