Alright, let's work through 1191 times 3870 step by step
1191 × 3870 = 3870 × (1191)
+ 3870 × 1 what gives us 3870
+ 3870 × 90 producing 348300
+ 3870 × 100 producing 387000
+ 3870 × 1000 producing 3870000

= 4609170
