Alright, let's work through 3206 times 1240 step by step
3206 × 1240 = 1240 × (3206)
+ 1240 × 6 yielding 7440
+ 1240 × 00 what gives us 0
+ 1240 × 200 what gives us 248000
+ 1240 × 3000 giving us 3720000

= 3975440
