What is mathematical literacy?
Mathematical literacy is defined by the OECD as the capacity

"to identify, understand and engage in mathematics, and to make well-founded judgements about the role that mathematics plays in an individual's current and future private life, occupational life, social life with peers and relatives, and life as a constructive, concerned and reflective citizen".

Knowledge and Skills for Life: First Results from PISA 2000. OECD, p. 22
(http://www.oecd.org/dataoecd/44/53/33691596.pdf)

The PISA conceptual framework differentiates between three aspects within the domain of mathematics which are of central importance for the appropriate use of mathematics in realistic everyday problems:

1. Content areas
   • Quantity concerns all types of quantification with numbers, the understanding of relative size and the recognition of numerical patterns.
   • Change and relationships involves mathematical representations of change as well as various kinds of functional relationships between mathematical objects.
   • Space and shape relates to all forms of spatial and geometric configurations, shapes and patterns.
   • Uncertainty involves mathematical phenomena and situations which include statistical data in which chance plays a role.
2. Competency clusters
   • Reproduction
   • Connections
   • Reflection
3. Situations
   • Personal situations
   • Educational and occupational situations
   • Public situations
   • Scientific situations

Sample items can be found here