Common Core Standards: Mathematical Concepts Your Child Should Learn in Kindergarten
There are certain mathematical concepts that a child will encounter at each grade level that lends to their ability to satisfy the Common Core Standards. In kindergarten, math focuses on two areas:

Whole numbers: Whole numbers are those that aren’t fractions; for example, 1 and 99 are whole numbers, whereas 1/3 is not. Kindergarten students are expected to be able to count, use written numerals to represent numbers, and combine and remove objects to grasp the concepts of addition and subtraction without necessarily solving written equations, such as 2 + 2 = 4.

Shapes: By the end of kindergarten, students should be familiar with twodimensional shapes (circles, squares, triangles, and so on), threedimensional shapes (cubes, cylinders, and cones, for example), orientation (the position of a shape in the space it occupies), and spatial relationships (the position of shapes in relation to other shapes). Students are also expected to know the vocabulary or how to talk about shapes and related concepts.
Kindergarten math standards focus on only two areas (numbers and shapes), but the essential concepts and skills are divided into five different domains.
Counting and cardinality
In kindergarten, the focus is on counting with cardinal numbers (1, 2, 3, and so on) and ordinal numbers (1st, 2nd, 3rd, and so on). Students discover what numbers are and what they represent, how to write numerals from 0 to 20, and how to count from 1 to 100 by ones and tens.
Students also use numbers to count objects in a group and discover how to count higher to add an item to the group. Understanding the relationships between the numeral and how a number represents a certain quantity also enables them to compare the number of items in different groups, whether they are working with manipulative objects or numbers on a page.
Write the number 5 on a piece of paper. Ask your child to tell what the number means or represents. Provide objects to count out to show you how many 5 represents. Practice counting from 1 to 100, sometimes adding a degree of difficulty by alternating the number used to start the series. Encourage your child to count everyday objects in your home with emphasis on the final number.
Operations and algebraic thinking
At the kindergarten level, the operations and algebraic thinking domain applies mostly to addition and subtraction. Students are expected to understand the concept of decomposing numbers — showing that a number, such as 9, can be separated into parts, such as 4 and 5. This is more than just learning basic addition facts, as students demonstrate their understanding of the numbers that can combine to make a larger number.
Students also practice adding and subtracting with objects, fingers, verbal explanations, drawings, acting out situations, and so on.
Use ordinary objects, such as forks or spoons, to practice addition and subtraction. Mix it up by creating a gamelike atmosphere and see how quickly your child can complete basic addition and subtraction using numbers from 1 to 5. Use ordinary objects to demonstrate the concept of decomposing a number; for example, divide a group of five marbles into two groups, one with three and the other with two marbles.
Number and operations in base ten
In kindergarten, base ten refers to the value of a number from 1 to 9 according to its position in a number greater than 9. Students practice using place value with numbers from 11 to 19 by describing that the number in the tens place is made up of ten ones, and the number in the ones place is counted by ones.
Reinforce your child’s understanding of place value by writing a number from 11 to 19 on a piece of paper and then having your child draw or write the total number or quantity represented by the left and right numerals. Have your child double check his answer by counting all of the objects he draws or writes.
To raise the bar, have your child decompose numbers from 11 to 19 using one group of 10 and another group for the rest.
Measurement and data
At the kindergarten level, the measurement and data domain concentrates on two concepts and skills:

An object’s comparable attributes, such as length, height, and weight.

Measuring and comparing measurable attributes in two objects, such as the lengths of two crayons.
Students are expected to compare objects for different purposes and to describe their results. They also use their understanding of measurements to compare, contrast, or classify multiple objects based on how their attributes (such as length, height, and so on) are related.
Have your child compare the attributes of different objects and rank them based on their length, height, width, weight, and so on. Even though comparing and contrasting these characteristics is a major emphasis in kindergarten, you can extend his understanding of measurements by introducing him to basic tools, such as a ruler, and allowing him to practice taking accurate measurements.
Geometry
Kindergarten students are expected to describe shapes and where objects are located in relation to other objects, along with composing simple shapes to form larger shapes. Students use these concepts to build a sense of familiarity with the names of objects, determine whether the objects exist in two or three dimensions, and recognize certain shapes in realworld settings.
Help your child become familiar with the shapes of commonly used objects and where they can be found in everyday life; for example, an orange is round (as described in two dimensions) or a sphere (in three dimensions).
Assist her in recognizing objects in the home environment that are the same as geometric shapes or that can be put together to make different shapes; for example, use paper, books, glasses or cups, and boxes to reinforce her ability to recognize shapes in two and three dimensions.