Alright, let's solve this math problem step by step. First, we have the number 420. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 6. So, we're going to take the number 420 and add it to itself 6 times.
Step 1: 0 + 420 = 420
Step 2: 420 + 420 = 840
Step 3: 840 + 420 = 1260
Step 4: 1260 + 420 = 1680
Step 5: 1680 + 420 = 2100
Step 6: 2100 + 420 = 2520

So, 420*6 = 2520