Alright, let's work through 4157 times 997 step by step
4157 × 997 = 997 × (4157)
+ 997 × 7 producing 6979
+ 997 × 50 yielding 49850
+ 997 × 100 giving us 99700
+ 997 × 4000 which equals 3988000

= 4144529
