"Those who fiddled with the phones performed 25 per cent better on the end-of-the-year algebra exam than those who used a slide rule, researchers found." -- Yes, but how well did these children perform in previous years (without the phone) in comparison to their colleagues? This trial shows nothing other than that the "researchers" gave phones to children who did well in algebra. I would be more interested in seeing if the phone could improve an at-risk child's standardized test scores or something like that.

I doubt it. However, practicing maths using a phone with maths software can help.

I attended an extra maths morning lesson free at my school and the teacher would cover the common basics of A level maths. He was a "fun" guy, lively and could keep the whole classes attention. This class was only run for a couple of weeks before the exams started.

If they included software that could do this same task then it's probably going to give some increase, maybe as much as 25% depending on the test.