Alright, let's work through 4122 times 1782 step by step
4122 × 1782 = 1782 × (4122)
+ 1782 × 2 resulting in 3564
+ 1782 × 20 which equals 35640
+ 1782 × 100 giving us 178200
+ 1782 × 4000 that is equal 7128000

= 7345404
