Alright, let's work through 7838 times 6543 step by step
7838 × 6543 = 6543 × (7838)
+ 6543 × 8 producing 52344
+ 6543 × 30 resulting in 196290
+ 6543 × 800 that results in 5234400
+ 6543 × 7000 that is equal 45801000

= 51284034
