OK, let's crack this. We're given 819 and our task is to multiply it by 7. Essentially, we'll be adding 819 to itself 7 times.
Step 1: 0 + 819 = 819
Step 2: 819 + 819 = 1638
Step 3: 1638 + 819 = 2457
Step 4: 2457 + 819 = 3276
Step 5: 3276 + 819 = 4095
Step 6: 4095 + 819 = 4914
Step 7: 4914 + 819 = 5733

So, 819*7 = 5733