Alright, let's work through 8298 times 8420 step by step
8298 × 8420 = 8420 × (8298)
+ 8420 × 8 yielding 67360
+ 8420 × 90 yielding 757800
+ 8420 × 200 producing 1684000
+ 8420 × 8000 giving us 67360000

= 69869160
