OK, let's work through this together. We're starting with 691 and we're going to multiply it by 4, which means we add 691 to itself 4 times.
Step 1: 0 + 691 = 691
Step 2: 691 + 691 = 1382
Step 3: 1382 + 691 = 2073
Step 4: 2073 + 691 = 2764

So, 691*4 = 2764