Alright, let's work through 6635 times 631 step by step
6635 × 631 = 631 × (6635)
+ 631 × 5 yielding 3155
+ 631 × 30 that is equal 18930
+ 631 × 600 which equals 378600
+ 631 × 6000 resulting in 3786000

= 4186685
