Alright, let's work through 7872 times 6824 step by step
7872 × 6824 = 6824 × (7872)
+ 6824 × 2 that is equal 13648
+ 6824 × 70 what gives us 477680
+ 6824 × 800 that is equal 5459200
+ 6824 × 7000 giving us 47768000

= 53718528
