YOUR columnist Rosemary Goring posits a theory on improving the maths and science achievements of schoolgirls (“Single-sex science classes is an experiment worth trying”, Opinion, The Herald, February 14).

I believe this can be expressed by the following equation: XX - XY = HM + S, where X and Y refer to gender, HM refer to Higher Mathematics and S refers to Science.

R Russell Smith,

96 Milton Road,

Kilbirnie.