No problem, we've got 2121 and 1906 to multiply
2121 × 1906 = 1906 × (2121)
+ 1906 × 1 resulting in 1906
+ 1906 × 20 that is equal 38120
+ 1906 × 100 what gives us 190600
+ 1906 × 2000 resulting in 3812000

= 4042626
