$12+13=25$12+13=25
Use this to find:
$12+23=\editable{}$12+23=
$12+33=\editable{}$12+33=
$12+43=\editable{}$12+43=
$12+73=\editable{}$12+73=
Use what you know about subtracting to find:
$11+25=36$11+25=36
Use this to find:
We know that $38-25=13$38−25=13.
Use this to find: