Alright, let's work through 8340 times 9121 step by step
8340 × 9121 = 9121 × (8340)
+ 9121 × 0 that is equal 0
+ 9121 × 40 which equals 364840
+ 9121 × 300 that results in 2736300
+ 9121 × 8000 yielding 72968000

= 76069140
