Alright, let's work through 7820 times 8077 step by step
7820 × 8077 = 8077 × (7820)
+ 8077 × 0 that results in 0
+ 8077 × 20 that results in 161540
+ 8077 × 800 giving us 6461600
+ 8077 × 7000 which equals 56539000

= 63162140
