Alright, let's work through 2157 times 2168 step by step
2157 × 2168 = 2168 × (2157)
+ 2168 × 7 what gives us 15176
+ 2168 × 50 which equals 108400
+ 2168 × 100 that equals 216800
+ 2168 × 2000 what gives us 4336000

= 4676376
