Alright, let's work through 3587 times 647 step by step
3587 × 647 = 647 × (3587)
+ 647 × 7 that equals 4529
+ 647 × 80 yielding 51760
+ 647 × 500 that is equal 323500
+ 647 × 3000 which equals 1941000

= 2320789
