When adding two digit numbers u will be looking at the ones and deciding if they can regroup them for a ten. You might want to equate regrouping with trading a term that you will understand immediately you will begin to add 2 digit numbers by using ten and ones blocks. And the answer is (107)
When you do an addition problem like 77 + 23 you put each number on top of the other in either way you want to put (In addition) so if you reach a number that goes to ten or up to nineteen you will have to add a one to the seven if you end up at 20 you have to add 2 to the 7 but the only, but your case is different, You would have to add four plus three giving you a seven and and 6 plus 4 giving you a 10 so just put the 10 to the 7 giving you 107
