Mathematics : Addition ++

Are your kids practicing their simple addition and subtraction sums and getting a wee bit tired of it? Here are two not so conventional looking sums that might make them sit up like they did to my two:

Try to solve for H, E and A if

HE
HE
HE
+HE
-----
HA
-----

or


What is C if

A
B
+C
----
AB
----

These are guaranteed encores! ... I am off hunting for more!