Alright, let's work through 1640 times 2626 step by step
1640 × 2626 = 2626 × (1640)
+ 2626 × 0 that equals 0
+ 2626 × 40 which equals 105040
+ 2626 × 600 producing 1575600
+ 2626 × 1000 that results in 2626000

= 4306640
