No problem, we've got 3981 and 5146 to multiply
3981 × 5146 = 5146 × (3981)
+ 5146 × 1 what gives us 5146
+ 5146 × 80 that is equal 411680
+ 5146 × 900 that is equal 4631400
+ 5146 × 3000 giving us 15438000

= 20486226
