No problem, we've got 3921 and 2378 to multiply
3921 × 2378 = 2378 × (3921)
+ 2378 × 1 that is equal 2378
+ 2378 × 20 what gives us 47560
+ 2378 × 900 giving us 2140200
+ 2378 × 3000 giving us 7134000

= 9324138
