OK, let's crack this. We're given 1000 and our task is to multiply it by 3. Essentially, we'll be adding 1000 to itself 3 times.
Step 1: 0 + 1000 = 1000
Step 2: 1000 + 1000 = 2000
Step 3: 2000 + 1000 = 3000

So, 1000*3 = 3000