Alright, let's work through 7718 times 1638 step by step
7718 × 1638 = 1638 × (7718)
+ 1638 × 8 producing 13104
+ 1638 × 10 yielding 16380
+ 1638 × 700 that is equal 1146600
+ 1638 × 7000 that results in 11466000

= 12642084
