Alright, let's work through 7831 times 840 step by step
7831 × 840 = 840 × (7831)
+ 840 × 1 resulting in 840
+ 840 × 30 that equals 25200
+ 840 × 800 yielding 672000
+ 840 × 7000 giving us 5880000

= 6578040
