Alright, let's work through 7640 times 9641 step by step
7640 × 9641 = 9641 × (7640)
+ 9641 × 0 that results in 0
+ 9641 × 40 what gives us 385640
+ 9641 × 600 producing 5784600
+ 9641 × 7000 giving us 67487000

= 73657240
