Let's roll up our sleeves and solve this. We have 821 and we're going to multiply it by 6, essentially adding 821 to itself 6 times.
Step 1: 0 + 821 = 821
Step 2: 821 + 821 = 1642
Step 3: 1642 + 821 = 2463
Step 4: 2463 + 821 = 3284
Step 5: 3284 + 821 = 4105
Step 6: 4105 + 821 = 4926

So, 821*6 = 4926