Possible Clues:

• Science of numbers etc
• Does the summer want this hat in manuscript? (5)
• Sounds as if there's some 33 across in this
• Some of it is sham, but all of it has some sound
• Numbers subject
• Arithmetic etc
• There's some work there, by the sound of it
• Science dealing with quantity and shapes, in short
• That's got, by the sound of it, some figures
• That's some sound work