No problem, we've got 3984 and 7890 to multiply
3984 × 7890 = 7890 × (3984)
+ 7890 × 4 that results in 31560
+ 7890 × 80 that is equal 631200
+ 7890 × 900 which equals 7101000
+ 7890 × 3000 which equals 23670000

= 31433760
