Misenumerate

To avoid tedious repetitious ^([sic]) the possibility that at least some of those “recovered/omitted” were not altogether “nonenumerated in 1951/1961”, but may have been misenumerated in the wrong age groups is not repeated at every relevant point.

For the word problem above, for example, a child may have difficulty representing the minuend accurately (put up four fingers or put out four blocks instead of five), take away one object too many or too few, or misenumerate the remaining objects.

Prior to 1881, the census listed significant numbers of children at home. While some of these children were misenumerated, many performed domestic work to ease the burden on the mother.