I will show you how to do the A and B. Then from there I hope you can do the rest. If you still need help after, let me know.
First you must know what a tenth means, a tenth is 1/10 (one out of ten equal parts of a whole).
A. 1 tenths + 2 tenths = 3 tenths
1/10 + 2/10 = 3/10
B. 14 tenths + 9 tenths = 23 tenths
14/10 + 9/10 = 23/10
3 ones and 2 tenths
