OK, let's work through this together. We're starting with 881 and we're going to multiply it by 4, which means we add 881 to itself 4 times.
Step 1: 0 + 881 = 881
Step 2: 881 + 881 = 1762
Step 3: 1762 + 881 = 2643
Step 4: 2643 + 881 = 3524

So, 881*4 = 3524