Alright, let's work through 4135 times 9889 step by step
4135 × 9889 = 9889 × (4135)
+ 9889 × 5 what gives us 49445
+ 9889 × 30 what gives us 296670
+ 9889 × 100 what gives us 988900
+ 9889 × 4000 what gives us 39556000

= 40891015
