Alright, let's work through 1978 times 5105 step by step
1978 × 5105 = 5105 × (1978)
+ 5105 × 8 that results in 40840
+ 5105 × 70 that results in 357350
+ 5105 × 900 that equals 4594500
+ 5105 × 1000 producing 5105000

= 10097690
