Posted by mythreyee on Tuesday, February 26, 2013 at 3:50pm.
one 10 is regrouped as 10 ones in each number. work backwards. write the number with 10 ones grouped as 1 ten again.
1.tens ones
5 15

3rd grade math  summer, Wednesday, February 27, 2013 at 4:03pm
regroup the ten ones as 1 ten again