Alright, let's work through 5388 times 78 step by step
5388 × 78 = 78 × (5388)
+ 78 × 8 resulting in 624
+ 78 × 80 what gives us 6240
+ 78 × 300 which equals 23400
+ 78 × 5000 resulting in 390000

= 420264
