Alright, let's work through 1037 times 640 step by step
1037 × 640 = 640 × (1037)
+ 640 × 7 that is equal 4480
+ 640 × 30 what gives us 19200
+ 640 × 000 that equals 0
+ 640 × 1000 that results in 640000

= 663680
