 Admission to Carre 's is through the eleven @-@ plus examination and entry is limited to boys in the lower school , although the Sixth Form is co @-@ educational . The total number of pupils on roll in 2013 was <unk> , of which 240 were in the Sixth Form . Teaching follows the National Curriculum and pupils generally sit examinations for ten or eleven General Certificate of Secondary Education ( GCSE ) qualifications in Year Eleven ( aged 15 – 16 ) . They have a choice of three or four A @-@ levels in the sixth form , which is part of the Sleaford Joint Sixth Form consortium between Carre 's and St George 's Academy . Of the 2013 cohort , 100 % of pupils achieved at least five GCSEs at grade A * <unk> and 96 % achieved that including English and <unk> GCSEs , the eighth highest percentage in Lincolnshire . An Office for Standards in Education , Children 's Services and <unk> ( <unk> ) inspection in 2013 graded Carre 's " good " overall with " outstanding " features . 
