why you should record a 1 in the tens column when you regroup in an addition problem

EX: 29

+24

= 53

If u add the right side and it's over 9 then you have to put a 1 or whatever the first number is bc you can't put the full number which means you have to take the first number which is a 1 in my ex and put it in the left column. You should do this because u can't put the full. two digits down you have to regroup the 1.

Because any number times itself is the number