In Bangladesh gross and net enrolment rates are used to measure overage and underage enrolment in the education system. However, due to the limits of these methods in exploring the issue of age in grade, the paper uses the CREATE Community and School Survey (COMSS) data from Bangladesh. COMSS was a longitudinal survey of 6,696 households with 9,045 children of 4-15 years old in 2007 and 2009. The paper shows that 69.4 percent of 6-15 year old children, enrolled in primary and secondary schools in 2007 are age in grade incongruent and that in the early grades of primary school this proportion is even higher. Age in grade incongruent children come from relatively low income families and have relatively poor health. Age in grade incongruent children attend school irregularly and perform worse than the congruent children of the same grade. Less than 50 percent of primary Grade 1, 2 and 3 children progress to the next grade on time. Slow progressing children also come from relatively low income families, have relatively poor health and inadequate learning materials compared to regularly progressing children of their grade group. The slow progressing children attend school irregularly compared to the regularly progressing group and get less primary school stipend money. Both these age in grade incongruent and slow progressing children are increasing the number of "silently excluded" children in classrooms. (Contains 5 tables and 17 figures.)