Addends

15 clues
Sum parts
Units in a sum
Numbers summed
Summer figures?
Total producers
Some sum numbers
Calculator figures
Figures above a line
Math problem numbers
Numbers used in sums
Numbers to be summed
Numbers in additions
The 1 and 2 in 1 + 2 = 3
Numbers to be summed, in math
All the parts of a column except the bottom