OK, let's work through this together. We're starting with 866 and we're going to multiply it by 6, which means we add 866 to itself 6 times.
Step 1: 0 + 866 = 866
Step 2: 866 + 866 = 1732
Step 3: 1732 + 866 = 2598
Step 4: 2598 + 866 = 3464
Step 5: 3464 + 866 = 4330
Step 6: 4330 + 866 = 5196

So, 866*6 = 5196