First we can either add 19 and 11, or we can do this another way.
19 + 11 = 30 To find how much thirty tens are, just add a 0 on the end of 30: 300
The other longer way to do it is: add a 0 to 19: 190, then add a 0 to 11: 110
110 + 190 = 300
There is your answer!
