Long /oo/ and Short /oo/ Sorting Mats Students sort /oo/ sound pictures onto two separate sorting mats. They must listen carefully to the /oo/ sound they hear to determine whether the picture card should be placed on the short or long sorting mat. This activity works well in both small groups and as a whole class! You may also be interested in our /oo/ sounds board game ‘Hoot Hoot’. Check it out!