Alright, let's work through 9870 times 852 step by step
9870 × 852 = 852 × (9870)
+ 852 × 0 producing 0
+ 852 × 70 that is equal 59640
+ 852 × 800 what gives us 681600
+ 852 × 9000 that is equal 7668000

= 8409240
