Alright, let's work through 2001 times 668 step by step
2001 × 668 = 668 × (2001)
+ 668 × 1 what gives us 668
+ 668 × 00 what gives us 0
+ 668 × 000 which equals 0
+ 668 × 2000 resulting in 1336000

= 1336668
