elementary lesson
nounUK /ˌel.ɪˈmen.tər.i ˈles.ən/
US /ˌel.əˈmen.tɚ.i ˈles.ən/
A simple lesson that teaches the first, basic things about a subject.
The teacher gave the children an elementary lesson on how plants grow.
OTHER MEANINGS
2. A short, easy teaching unit for young students.
Each elementary lesson in the workbook takes only ten minutes.
3. A first, simple warning or piece of advice about something.
Losing that game was an elementary lesson in teamwork for the new players.
4. A basic moral or principle taught in a plain way.
The story offers an elementary lesson about honesty.