Alright, let's work through 6688 times 6402 step by step
6688 × 6402 = 6402 × (6688)
+ 6402 × 8 producing 51216
+ 6402 × 80 yielding 512160
+ 6402 × 600 yielding 3841200
+ 6402 × 6000 resulting in 38412000

= 42816576
