Let's roll up our sleeves and solve this. We have 28 and we're going to multiply it by 4, essentially adding 28 to itself 4 times.
Step 1: 0 + 28 = 28
Step 2: 28 + 28 = 56
Step 3: 56 + 28 = 84
Step 4: 84 + 28 = 112

So, 28*4 = 112