Alright, let's work through 8131 times 9869 step by step
8131 × 9869 = 9869 × (8131)
+ 9869 × 1 that equals 9869
+ 9869 × 30 which equals 296070
+ 9869 × 100 giving us 986900
+ 9869 × 8000 that results in 78952000

= 80244839
