No problem, we've got 1639 and 7965 to multiply
1639 × 7965 = 7965 × (1639)
+ 7965 × 9 yielding 71685
+ 7965 × 30 that is equal 238950
+ 7965 × 600 what gives us 4779000
+ 7965 × 1000 that results in 7965000

= 13054635
