OK, let's crack this. We're given 787 and our task is to multiply it by 4. Essentially, we'll be adding 787 to itself 4 times.
Step 1: 0 + 787 = 787
Step 2: 787 + 787 = 1574
Step 3: 1574 + 787 = 2361
Step 4: 2361 + 787 = 3148

So, 787*4 = 3148