Alright, let's work through 6491 times 5640 step by step
6491 × 5640 = 5640 × (6491)
+ 5640 × 1 what gives us 5640
+ 5640 × 90 what gives us 507600
+ 5640 × 400 giving us 2256000
+ 5640 × 6000 that is equal 33840000

= 36609240
