Let's get this math done. We have 503 and we're going to multiply it by 3. This is the same as taking 503 and adding it to itself 3 times.
Step 1: 0 + 503 = 503
Step 2: 503 + 503 = 1006
Step 3: 1006 + 503 = 1509

So, 503*3 = 1509