Alright, let's work through 5207 times 640 step by step
5207 × 640 = 640 × (5207)
+ 640 × 7 that equals 4480
+ 640 × 00 giving us 0
+ 640 × 200 giving us 128000
+ 640 × 5000 yielding 3200000

= 3332480
