What is the addend for 22+49

Both 22 and 49 are addends.

From Google:

ad·dend
/ˈaˌdend/Submit
nounMATHEMATICS•COMPUTING
a number that is added to another.
"as its name suggests, the Accumulator ‘accumulates’ by keeping its addend in memory and incrementing by the addend it receives from another transmitting unit"