Alright, let's work through 85097980 times 77003251 step by step
85097980 × 77003251 = 77003251 × (85097980)
+ 77003251 × 0 that equals 0
+ 77003251 × 80 that is equal 6160260080
+ 77003251 × 900 yielding 69302925900
+ 77003251 × 7000 that equals 539022757000
+ 77003251 × 90000 that results in 6930292590000
+ 77003251 × 000000 producing 0
+ 77003251 × 5000000 resulting in 385016255000000
+ 77003251 × 80000000 what gives us 6160260080000000

= 6552821113532980
