Alright, let's work through 8120 times 8210 step by step
8120 × 8210 = 8210 × (8120)
+ 8210 × 0 resulting in 0
+ 8210 × 20 that equals 164200
+ 8210 × 100 which equals 821000
+ 8210 × 8000 what gives us 65680000

= 66665200
