Alright, let's solve this math problem step by step. First, we have the number 70. 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 70 and add it to itself 4 times.
Step 1: 0 + 70 = 70
Step 2: 70 + 70 = 140
Step 3: 140 + 70 = 210
Step 4: 210 + 70 = 280

So, 70*4 = 280