Alright, let's work through 7715 times 1788 step by step
7715 × 1788 = 1788 × (7715)
+ 1788 × 5 that equals 8940
+ 1788 × 10 giving us 17880
+ 1788 × 700 what gives us 1251600
+ 1788 × 7000 that is equal 12516000

= 13794420
