Alright, let's work through 8472 times 7991 step by step
8472 × 7991 = 7991 × (8472)
+ 7991 × 2 producing 15982
+ 7991 × 70 that results in 559370
+ 7991 × 400 yielding 3196400
+ 7991 × 8000 that is equal 63928000

= 67699752
