Alright, let's work through 7997 times 7640 step by step
7997 × 7640 = 7640 × (7997)
+ 7640 × 7 that is equal 53480
+ 7640 × 90 which equals 687600
+ 7640 × 900 what gives us 6876000
+ 7640 × 7000 giving us 53480000

= 61097080
