Alright, let's work through 9912 times 1215 step by step
9912 × 1215 = 1215 × (9912)
+ 1215 × 2 what gives us 2430
+ 1215 × 10 that equals 12150
+ 1215 × 900 that results in 1093500
+ 1215 × 9000 yielding 10935000

= 12043080
