OK, let's work through this together. We're starting with 863 and we're going to multiply it by 3, which means we add 863 to itself 3 times.
Step 1: 0 + 863 = 863
Step 2: 863 + 863 = 1726
Step 3: 1726 + 863 = 2589

So, 863*3 = 2589