No problem, we've got 4185 and 4200 to multiply
4185 × 4200 = 4200 × (4185)
+ 4200 × 5 yielding 21000
+ 4200 × 80 which equals 336000
+ 4200 × 100 which equals 420000
+ 4200 × 4000 resulting in 16800000

= 17577000
