Really good one for us in schools. This symbol means pen or pencil 筆.
The character 筆（ㄅㄧˇ） means pen or pencil. Here is the stroke order animation and pronunciation. Here are the individual strokes for writing the character. Here is the definition in Taiwanese Mandarin. Here is the evolution of 筆.
筆（ㄅㄧˇ）劃（ㄏㄨㄚˋ） – number of strokes in a Chinese character
筆（ㄅㄧˇ）名（ㄇㄧㄥˊ） – a pen-name
筆（ㄅㄧˇ）試（ㄕˋ） – a written exam