Let's get this math done. We have 489 and we're going to multiply it by 10. This is the same as taking 489 and adding it to itself 10 times.
Step 1: 0 + 489 = 489
Step 2: 489 + 489 = 978
Step 3: 978 + 489 = 1467
Step 4: 1467 + 489 = 1956
Step 5: 1956 + 489 = 2445
Step 6: 2445 + 489 = 2934
Step 7: 2934 + 489 = 3423
Step 8: 3423 + 489 = 3912
Step 9: 3912 + 489 = 4401
Step 10: 4401 + 489 = 4890

So, 489*10 = 4890