Student work with number after is important because it increases student flexibility with the number sequence and the ability to start counting sequences at various points. Initially students may need a number line to locate the number after; students may also do some 'sub-vocal' counting (sort of like counting under their breath) from another number to give them a 'running start' which helps them carry on the sequence. Sub-vocalization is a common student strategy that should be noted when assessing a student's facility with number after. The students should reach a point when they 'just know' the number after orally and do not need the number line support or the additional counting.