Alright, let's work through 6247 times 4066 step by step
6247 × 4066 = 4066 × (6247)
+ 4066 × 7 that is equal 28462
+ 4066 × 40 yielding 162640
+ 4066 × 200 that is equal 813200
+ 4066 × 6000 that equals 24396000

= 25400302
