Answer:
Step-by-step explanation:
First your gonna brake up each number and seperate them for example
28
29
42
then your going to add up the ones side, 8,9,2, to get 19.
Then your going to add the tens side, 2,2,4, to get 8.
take the one from 19 and put it in the tens place to get 9 in the tens and 9 in the ones.
put 9 and 9 together to get 99.
