Reys P. answered • 11/03/15

Tutor

New to Wyzant
Mathematics Tutor: Building Understanding and Comprehension

In 9+10, you keep the 9 since its in the ones place.

Since there is only a 9 and no other number next to it, the 1 in 10 is added onto the 9 to form 19.

You can think of it like there is an invisible 0 in front of 9 to hold the tens place (09) so that's why we add on the 1 to that invisible 0 to get 19.

Here is how it would look stacking the numbers to add them:

10

+09

19