We're going to solve 1644 multiplied by 7255
1644 × 7255 = 7255 × (1644)
+ 7255 × 4 what gives us 29020
+ 7255 × 40 producing 290200
+ 7255 × 600 which equals 4353000
+ 7255 × 1000 resulting in 7255000

= 11927220
