Sure thing, let's get straight to it. We start with 495 and we're going to multiply it by 20, which means adding 495 to itself 20 times.
Step 1: 0 + 495 = 495
Step 2: 495 + 495 = 990
Step 3: 990 + 495 = 1485
Step 4: 1485 + 495 = 1980
Step 5: 1980 + 495 = 2475
Step 6: 2475 + 495 = 2970
Step 7: 2970 + 495 = 3465
Step 8: 3465 + 495 = 3960
Step 9: 3960 + 495 = 4455
Step 10: 4455 + 495 = 4950
Step 11: 4950 + 495 = 5445
Step 12: 5445 + 495 = 5940
Step 13: 5940 + 495 = 6435
Step 14: 6435 + 495 = 6930
Step 15: 6930 + 495 = 7425
Step 16: 7425 + 495 = 7920
Step 17: 7920 + 495 = 8415
Step 18: 8415 + 495 = 8910
Step 19: 8910 + 495 = 9405
Step 20: 9405 + 495 = 9900

So, 495*20 = 9900