Alright, let's work through 1673 times 778 step by step
1673 × 778 = 778 × (1673)
+ 778 × 3 producing 2334
+ 778 × 70 which equals 54460
+ 778 × 600 which equals 466800
+ 778 × 1000 giving us 778000

= 1301594
