Alright, let's work through 80891870 times 87114353 step by step
80891870 × 87114353 = 87114353 × (80891870)
+ 87114353 × 0 that equals 0
+ 87114353 × 70 which equals 6098004710
+ 87114353 × 800 what gives us 69691482400
+ 87114353 × 1000 resulting in 87114353000
+ 87114353 × 90000 giving us 7840291770000
+ 87114353 × 800000 yielding 69691482400000
+ 87114353 × 0000000 that equals 0
+ 87114353 × 80000000 giving us 6969148240000000

= 7046842918010110
