Alright, let's work through 7800 times 3631 step by step
7800 × 3631 = 3631 × (7800)
+ 3631 × 0 that is equal 0
+ 3631 × 00 resulting in 0
+ 3631 × 800 that results in 2904800
+ 3631 × 7000 giving us 25417000

= 28321800
