index
diary index
☐☐+☐☐=
☐☐☐+☐☐☐=
☐☐-☐☐=
☐☐☐-☐☐☐=
☐☐×☐=
☐☐×☐☐=
☐☐÷☐=
☐☐☐÷☐=
☐☐☐☐÷☐☐=