Alright, let's work through 2143 times 7998 step by step
2143 × 7998 = 7998 × (2143)
+ 7998 × 3 resulting in 23994
+ 7998 × 40 resulting in 319920
+ 7998 × 100 yielding 799800
+ 7998 × 2000 producing 15996000

= 17139714
