Explain why you should récord a 1 in the tens columna when you regroup in addition problem

You should write a 1 because I f what you add is 11, 12, 13, 14, 15, 16, 17, 18, or 19 there is a 1 in the front of the numbers so you must put a 1 but if the number was 76 the number in the front is 7 so you would put 7 on the tens column.