OK, let's work through this together. We're starting with 686 and we're going to multiply it by 6, which means we add 686 to itself 6 times.
Step 1: 0 + 686 = 686
Step 2: 686 + 686 = 1372
Step 3: 1372 + 686 = 2058
Step 4: 2058 + 686 = 2744
Step 5: 2744 + 686 = 3430
Step 6: 3430 + 686 = 4116

So, 686*6 = 4116