Alright, let's work through 4187 times 154 step by step
4187 × 154 = 154 × (4187)
+ 154 × 7 what gives us 1078
+ 154 × 80 giving us 12320
+ 154 × 100 resulting in 15400
+ 154 × 4000 yielding 616000

= 644798
