Here is a list of idioms about schools and learning.

Pass with flying colors

To pass with flying colors is to pass with a high score.

• She passed the entrance test with flying colors and secured admission in a prestigious college.

Play hooky

To play hooky is to not go to school

• The boys would play hooky and visit game parlors in the afternoon.

Put one’s thinking cap on

To put your thinking cap on is to start thinking in a serious manner.

• The boy put his thinking cap on and tried to come up with a catchy slogan.

Read to oneself

To read to oneself is to read silently.

• I spent a quiet afternoon at home reading to myself.

Read through something

To read through something is to read the whole of it.

• Before you start writing the test you should read through the questions.

School of hard knocks

This expression is used to refer to the experience of learning from real life.

• The boy left school at a young age, but he continued to learn in the school of hard knocks.

School of thought

This expression is used to refer to a particular way of thinking.

Show of hands

Used to refer to a kind of voting that involves the raising of hands.
After a show of hands, they decided to abandon the trip.

Teach your grandmother to suck eggs

To teach your grandmother to suck eggs is to try to teach them something they know better than you.