Let's get this math done. We have 450 and we're going to multiply it by 4. This is the same as taking 450 and adding it to itself 4 times.
Step 1: 0 + 450 = 450
Step 2: 450 + 450 = 900
Step 3: 900 + 450 = 1350
Step 4: 1350 + 450 = 1800

So, 450*4 = 1800