No problem, we've got 3900 and 7023 to multiply
3900 × 7023 = 7023 × (3900)
+ 7023 × 0 what gives us 0
+ 7023 × 00 yielding 0
+ 7023 × 900 that equals 6320700
+ 7023 × 3000 yielding 21069000

= 27389700
