Dana wants to find the sum
3 4 6
4 2 1
+1 5 2
________
We will not regroup this ones place because the sum of the digits in the ones place is not up to. It's just 6+1+2 = 9.
Therefore, 13a) No.
There is no regrouped tens to add, so we would not able to regroup the ones place.
Therefore, 13b) No.
We regroup the tens place because the sum of the digits in the ones place is upto to 10.
And 13c) Yes.
We add the regrouped hundred as we regrouped the ones place.
Therefore,
13 D) Yes.
