Alright, let's work through 3945 times 651 step by step
3945 × 651 = 651 × (3945)
+ 651 × 5 which equals 3255
+ 651 × 40 giving us 26040
+ 651 × 900 that equals 585900
+ 651 × 3000 giving us 1953000

= 2568195
