Question

Why we multiply the readings of ammeter and voltmeter by thier least count

Answer 1

All voltmeters and ammeters have scale starting from 0 to 100 or you may consider any value.  Let suppose  scale is 0 10 30 40 amps.  Now to get least couldnt just  see the number of divisions between 0 and, 1st scale that is 10 and if there are 10 divisions divided First number by  10

Answer 2

All voltmeters and ammeters have scale starting from 0 to 100 or you may consider any value.  Let suppose  scale is 0 10 30 40 amps.  Now to get least couldnt just  see the number of divisions between 0 and, 1st scale that is 10 and if there are 10 divisions divided First number by  10 .