Alright, let's work through 9881 times 8509 step by step
9881 × 8509 = 8509 × (9881)
+ 8509 × 1 that equals 8509
+ 8509 × 80 what gives us 680720
+ 8509 × 800 resulting in 6807200
+ 8509 × 9000 that equals 76581000

= 84077429
