The small numbers students have been working with up until the 1st grade are used and expanded upon here by learning strategies for adding and subtracting whole numbers. Length based and discrete objects are used to create models in order to learn to compare, take apart, take from, put together and add to differing situations as well as develop arithmetic operations including addition and subtraction.
Addition and subtraction, counting, and understanding the connections between these concepts is paramount in early 1st grade lesson plans and can build a strong foundation that will be needed later as the concepts and operations become increasingly difficult. It is also important to learn the relationships between the various functions in order to illustrate clearly that there is often many ways to solve the same problem.
Geometrical shapes are also studied and incorporated into other disciplines, and the composition of new shapes is introduced such as creating a quadrilateral from two triangles. This helps students build a better understanding of part-whole relationships as well as the concepts of composite and their original shapes. This combination of shapes also help students build a better understand of orientation and perspective and recognizing similar shapes from many different viewpoints. This must include an understanding of congruence and symmetry and a background including the measurement and identification of these concepts. Combining this with training in recognizing and understanding basic geometric attributes as well as teaching the necessary descriptive abilities to communicate them will give students a holistic view of basic mathematicsa.
The transitivity principle for indirect measurement will help students develop a background in the concepts of iterating an object as well basic measurement and description.
Adding within 100 as well as the subtraction of multiples of 10 will be in early lesson plans and students will need to develop and discuss generable methods of accurately completing these types of problems. Whole number comparison and solving problems based on relative number size will follow shortly after. These activities will lead students to understand the order of and relative magnitudes of whole numbers.