Alright, let's work through 3989 times 7898 step by step
3989 × 7898 = 7898 × (3989)
+ 7898 × 9 giving us 71082
+ 7898 × 80 that is equal 631840
+ 7898 × 900 that is equal 7108200
+ 7898 × 3000 what gives us 23694000

= 31505122
