Let's roll up our sleeves and solve this. We have 842 and we're going to multiply it by 5, essentially adding 842 to itself 5 times.
Step 1: 0 + 842 = 842
Step 2: 842 + 842 = 1684
Step 3: 1684 + 842 = 2526
Step 4: 2526 + 842 = 3368
Step 5: 3368 + 842 = 4210

So, 842*5 = 4210