Alright, let's solve this math problem step by step. First, we have the number 315. 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 315 and add it to itself 3 times.
Step 1: 0 + 315 = 315
Step 2: 315 + 315 = 630
Step 3: 630 + 315 = 945

So, 315*3 = 945