Acquiring a feel for the magnitude of the numbers being used is a part of fraction sense.
Fraction sense builds over time. It provides the basis for developing understanding of more sophisticated concepts and processes, such as equivalence and the addition of fractions.
Students who struggle with fractions, or rely on memorised procedures without understanding how they work, are often found to be lacking in fraction sense. Therefore, although fraction sense begins in the early years of school, the teaching activities designed to enhance fraction sense are likely be beneficial for a broad range of year levels.
Two important aspects of fraction sense are the ability to visualise and recognise the representations of commonly encountered fractions, and the understanding that a fraction is a number.
Further information about aspects of fraction sense can be found in the article Developing Fraction Sense using Digital Learning Objects on the AAMT website.