Alright, let's work through 1581 times 7159 step by step
1581 × 7159 = 7159 × (1581)
+ 7159 × 1 which equals 7159
+ 7159 × 80 what gives us 572720
+ 7159 × 500 giving us 3579500
+ 7159 × 1000 that equals 7159000

= 11318379
