Let's calculate 3891 x 1097
3891 × 1097 = 1097 × (3891)
+ 1097 × 1 that results in 1097
+ 1097 × 90 what gives us 98730
+ 1097 × 800 what gives us 877600
+ 1097 × 3000 which equals 3291000

= 4268427
