Alright, let's solve this math problem step by step. First, we have the number 126. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 4. So, we're going to take the number 126 and add it to itself 4 times.
Step 1: 0 + 126 = 126
Step 2: 126 + 126 = 252
Step 3: 252 + 126 = 378
Step 4: 378 + 126 = 504

So, 126*4 = 504