No problem, we've got 7815 and 3156 to multiply
7815 × 3156 = 3156 × (7815)
+ 3156 × 5 yielding 15780
+ 3156 × 10 yielding 31560
+ 3156 × 800 what gives us 2524800
+ 3156 × 7000 giving us 22092000

= 24664140
