Alright, let's work through 9999 times 392 step by step
9999 × 392 = 392 × (9999)
+ 392 × 9 yielding 3528
+ 392 × 90 that equals 35280
+ 392 × 900 that is equal 352800
+ 392 × 9000 that is equal 3528000

= 3919608
