Alright, let's work through 1944 times 2191 step by step
1944 × 2191 = 2191 × (1944)
+ 2191 × 4 what gives us 8764
+ 2191 × 40 what gives us 87640
+ 2191 × 900 that results in 1971900
+ 2191 × 1000 that equals 2191000

= 4259304
