OK, let's work through this together. We're starting with 331 and we're going to multiply it by 4, which means we add 331 to itself 4 times.
Step 1: 0 + 331 = 331
Step 2: 331 + 331 = 662
Step 3: 662 + 331 = 993
Step 4: 993 + 331 = 1324

So, 331*4 = 1324