Let's roll up our sleeves and solve this. We have 723 and we're going to multiply it by 8, essentially adding 723 to itself 8 times.
Step 1: 0 + 723 = 723
Step 2: 723 + 723 = 1446
Step 3: 1446 + 723 = 2169
Step 4: 2169 + 723 = 2892
Step 5: 2892 + 723 = 3615
Step 6: 3615 + 723 = 4338
Step 7: 4338 + 723 = 5061
Step 8: 5061 + 723 = 5784

So, 723*8 = 5784