Alright, let's work through 7809 times 9973 step by step
7809 × 9973 = 9973 × (7809)
+ 9973 × 9 that results in 89757
+ 9973 × 00 resulting in 0
+ 9973 × 800 yielding 7978400
+ 9973 × 7000 what gives us 69811000

= 77879157
