OK, let's work through this together. We're starting with 357 and we're going to multiply it by 4, which means we add 357 to itself 4 times.
Step 1: 0 + 357 = 357
Step 2: 357 + 357 = 714
Step 3: 714 + 357 = 1071
Step 4: 1071 + 357 = 1428

So, 357*4 = 1428