Sure thing! We've got 999 and we're gonna multiply it by 4. That's the same as adding 999 to itself 4 times.
Step 1: 0 + 999 = 999
Step 2: 999 + 999 = 1998
Step 3: 1998 + 999 = 2997
Step 4: 2997 + 999 = 3996

So, 999*4 = 3996