Alright, let's work through 3165 times 644 step by step
3165 × 644 = 644 × (3165)
+ 644 × 5 what gives us 3220
+ 644 × 60 that is equal 38640
+ 644 × 100 that is equal 64400
+ 644 × 3000 that results in 1932000

= 2038260
