Let's get this math done. We have 842 and we're going to multiply it by 4. This is the same as taking 842 and adding it to itself 4 times.
Step 1: 0 + 842 = 842
Step 2: 842 + 842 = 1684
Step 3: 1684 + 842 = 2526
Step 4: 2526 + 842 = 3368

So, 842*4 = 3368