Alright, let's work through 1389 times 7520 step by step
1389 × 7520 = 7520 × (1389)
+ 7520 × 9 which equals 67680
+ 7520 × 80 giving us 601600
+ 7520 × 300 which equals 2256000
+ 7520 × 1000 yielding 7520000

= 10445280
