Alright, let's work through 99519890 times 77700931 step by step
99519890 × 77700931 = 77700931 × (99519890)
+ 77700931 × 0 giving us 0
+ 77700931 × 90 that results in 6993083790
+ 77700931 × 800 that results in 62160744800
+ 77700931 × 9000 what gives us 699308379000
+ 77700931 × 10000 resulting in 777009310000
+ 77700931 × 500000 giving us 38850465500000
+ 77700931 × 9000000 resulting in 699308379000000
+ 77700931 × 90000000 that results in 6993083790000000

= 7732788106017590
