Alright, let's work through 78319307 times 12508339 step by step
78319307 × 12508339 = 12508339 × (78319307)
+ 12508339 × 7 resulting in 87558373
+ 12508339 × 00 what gives us 0
+ 12508339 × 300 producing 3752501700
+ 12508339 × 9000 what gives us 112575051000
+ 12508339 × 10000 giving us 125083390000
+ 12508339 × 300000 that is equal 3752501700000
+ 12508339 × 8000000 that is equal 100066712000000
+ 12508339 × 70000000 giving us 875583730000000

= 979644442201073
