No problem, we've got 1991 and 3690 to multiply
1991 × 3690 = 3690 × (1991)
+ 3690 × 1 that is equal 3690
+ 3690 × 90 what gives us 332100
+ 3690 × 900 giving us 3321000
+ 3690 × 1000 resulting in 3690000

= 7346790
