Operations and Algebraic Thinking As first graders continue to develop fluency with addition and subtraction, problem solving provides and opportunity for them to make sense of these operations using various situations and contexts. First graders extend their work from Kindergarten by developing more sophisticated strategies for addition by counting on rather than starting with 1, for subtraction counting back from a total (sum), and by composing and decomposing addends.
Numbers and Operations in Base Ten First graders build on Kindergarten work and begin to think of ten ones as a unit called a ten. Students continue to form initial understanding using a variety of materials then move to drawings and then to symbolic notation, including <, >, and =. They will find sums to 100 with understanding by using materials and dveloping strategies. Subtraction with two-digit numbers includes only differences smong multiples of 10 in first grade.
Measurement and Data First graders will learn what measurement is, how to measure length with nonstandard units, and how to align objects for comparison. Students will place nonstandard physical units sucha as cubes or straws end to end and coutn them to measure an object such as a student desk. At this level, first graders will also learn to use their own questions and collect, interpret, and anyalyze their data.
Geometry At the first grade level, the study of geometry features reasoning with shapes and their attributes. Students will learn three important ideas through the exploration of geometric and spatial concepts. First, students will identify defining attributes of two-dimensional and three-dimensional shapes. Second, first graders will use two-dimensional and three-dimensional shpaes to create a larger composite shape. Third, students will divide circles and rectangles into halves, fourths, quarters. As a result of their study, first graders will relate what they have learned to real-life situations.
The Common Core Mathematics Companion: The Standards Decoded Grades K-2 (2015). Authors: Linda M. Gojack and Ruth Harbin Miles