No problem, we've got 1804 and 9004 to multiply
1804 × 9004 = 9004 × (1804)
+ 9004 × 4 what gives us 36016
+ 9004 × 00 that equals 0
+ 9004 × 800 which equals 7203200
+ 9004 × 1000 which equals 9004000

= 16243216
