475 = 400 + 70 + 5
therefore
9 × 475 = 9 × (400 +70 + 5) = 9 × 400 + 9 × 70 + 9 × 5
=3600 + 630 + 45 = 4275
I think... It's better to use Distributive Property:
(a - b) × c = a × c - b × c
9 = 10 - 1
therefore:
(10 - 1) ×475 = 10 × 475 - 1 × 475 = 4750 - 475 = 4275