No problem, we've got 3783 and 4200 to multiply
3783 × 4200 = 4200 × (3783)
+ 4200 × 3 which equals 12600
+ 4200 × 80 that equals 336000
+ 4200 × 700 what gives us 2940000
+ 4200 × 3000 which equals 12600000

= 15888600
