States and school districts generally follow The National Council of Teachers
of Mathematics "Principles and Standards for School Mathematics"
(http://standards-e.nctm.org/1.0/89ces/Table_of_Contents.html).
In mathematics as in science, the standards are grouped into
grades K-4, 5-8 and 9-12.
With such a wide range of grades and math contend within
each of the three groups, you may want to check
with the teacher on their classes' specific knowledge and
math skills. For example, in K-4 the
standards discuss that all students should know how to multiply even
though that skill is generally not taught until the 3rd grade.
In high school, students following a college-bound curriculum may be
exposed to more advanced math concepts which have been noted.
For grades K-4 you can expect students to know
or be learning the following:
Students will have a basic understanding that math can be used
to solve problems in the classroom and in their day-to-day
living: like baseball statistics or counting change. They can
formulate basic questions regarding math such as "How many?"
or "How much?".
Students will be able to understand and use basic math symbols and
communicate math problems in everyday language. At this age level
they will understand that math problems can have exact answers or
can be estimations.
Students will understand the basics of whole number calculations using
addition, subtraction, multiplication and division, when each computational
method is used and the usage of a calculator.
Students will have been introduced to geometric shapes and spatial
visualization in 2 and 3 dimensions. They will have been
exposed to exercises on spatial relationships such as taking a 2
dimensional pattern and determining if a 3 dimensional shape can be
build from it.
Measurement, units and measuring tools are introduced to students.
Students at the upper end of the grades will be familiar
with the concepts of length, area, volume, as
well as temperature, angle, time, weight and mass.
Students will be familiar with collecting, organizing and basic graphic
representations of data.
Students will have been introduced to the concept of fractions.
For the early grades, this is considered a challenging concept
to communicate. For the older students, the relation between
fractions and decimals is introduced.
Students have been exposed to numerical and geometric pattern recognition.