No problem, we've got 1620 and 1931 to multiply
1620 × 1931 = 1931 × (1620)
+ 1931 × 0 resulting in 0
+ 1931 × 20 what gives us 38620
+ 1931 × 600 giving us 1158600
+ 1931 × 1000 that is equal 1931000

= 3128220
