Let's roll up our sleeves and solve this. We have 158 and we're going to multiply it by 4, essentially adding 158 to itself 4 times.
Step 1: 0 + 158 = 158
Step 2: 158 + 158 = 316
Step 3: 316 + 158 = 474
Step 4: 474 + 158 = 632

So, 158*4 = 632