Alright, let's work through 98899985 times 78912216 step by step
98899985 × 78912216 = 78912216 × (98899985)
+ 78912216 × 5 which equals 394561080
+ 78912216 × 80 giving us 6312977280
+ 78912216 × 900 which equals 71020994400
+ 78912216 × 9000 giving us 710209944000
+ 78912216 × 90000 which equals 7102099440000
+ 78912216 × 800000 yielding 63129772800000
+ 78912216 × 8000000 yielding 631297728000000
+ 78912216 × 90000000 giving us 7102099440000000

= 7804416978716760
