In this brief explanation, we will learn how to remove the last digit by using basic math
So the first and only step is to divide a number by 10
const number = 111;
const stripped = (number / 10) | 0;
//11
stripped is now 11.
There you go, job done
In case you have a string we will add parseInt
const number = "1423";
const stripped = (parseInt(number) / 10) | 0;
//142
And there you go, could not be simpler. God Speed!