OK, let's work through this together. We're starting with 667 and we're going to multiply it by 4, which means we add 667 to itself 4 times.
Step 1: 0 + 667 = 667
Step 2: 667 + 667 = 1334
Step 3: 1334 + 667 = 2001
Step 4: 2001 + 667 = 2668

So, 667*4 = 2668