The school, at the centre of a former council estate in Braintree, saw 81 per cent of its pupils reach the target of level 4 in maths, compared with 60 per cent in 1999 and just 41 per cent the year before.
In English, 78 per cent achieved level 4 this year, compared to 60 per cent last year and 57 per cent the year before.
However, the writing score was slightly lower than last year's.
An inspction in 1998 reported serious weaknesses. Head David Hume attributes the turnaround to staff and pupils' hard work.
Each year, pupils are given personal targets and the timetable has been changed, with an assembly at 10.05am breaking the morning into two shorter, more focused, sessions.
This year, Mr Hume used his booster-class money to fund more classroom help, rather than the voluntary sessions out of school, they tried last year.He said:
"With classroom help you can decide how to target the resources rather better."