Answer:
123.45 + 67.891 = 191.341
Explanation:
I don't know really know how to explain but I'll try to. So since 123.45 is the larger decimal so you put it first then below it you put 67.891.(not that it is necessary)
Then add a zero to 124.45. Meaning it will be 123.450. (It is the same number, we just have to add a zero there.)
Add then just add like you normally do. Just try doing it and you'll see.