When the lower digit is greater than the upper one.
With addition, you need to regroup in the event that there are more than 10 ones or 10 tens. In a subtraction, you must regroup whenever there are insufficient ones or tens to subtract.
You need to regroup when you have something like 46-39. You would cross out the 6 and make it a 16, because you are taking ten from the 4, then you cross out the 4 then make it a three, then you should get 7.
38
When the sum of the digits you are adding is 10 or larger.
because 1 is toobig
With addition, you need to regroup in the event that there are more than 10 ones or 10 tens. In a subtraction, you must regroup whenever there are insufficient ones or tens to subtract.
It is still a subtraction problem.
yes u can if you need too
You need to regroup when you have something like 46-39. You would cross out the 6 and make it a 16, because you are taking ten from the 4, then you cross out the 4 then make it a three, then you should get 7.
551
No
38
If the total in any column exceeds nine, you will have to regroup.
no
When the sum of the digits you are adding is 10 or larger.
Yes.
If the only operation you are working with is addition you don't need to. However, if dealing with a long list of numbers, it may be useful to regroup into tens and hundreds and other "round numbers" that you can sum together quickly at the end. For example 12 + 26 + 88 + 74 = 12 + 88 + 26 + 74 = (12 + 88) + (26 + 74) = 100 + 100 = 200