In Unit 1, Addition and Subtraction Within 10, students consider what it means to be a part of a math community. They build on their kindergarten experiences with addition and subtraction to deepen their understanding and develop fluency within 10. Students use a variety of tools, including Rekenreks, ten frames, linking cubes, and counters, to represent and solve problems and to support developing strategies. Students explore different ways to compose and decompose numbers and begin to build efficient strategies for adding and subtracting within 10. They solve familiar story problem situations using concrete objects, drawings, and equations to represent the mathematics in the problems. The work in this unit helps establish classroom routines for mathematical thinking and discussion while laying the foundation for continued work with addition and subtraction throughout the year, including solving a wider variety of story problem types and extending addition and subtraction to within 20 in later units.

In Unit 2, Adding and Subtracting With Story Problems, students build on their addition and subtraction work from Unit 1 as they learn to solve new types of story problems within 10. They make sense of problem solving situations, representing them mathematically using concrete objects and drawings, and explore how equations connect to the numbers in the problem. Students reason about quantities and relationships, developing a deeper understanding of how addition and subtraction are related while continuing to build fluency within 10. They strengthen their problem solving and reasoning skills, preparing them to extend this work with addition and subtraction within 20, as well as additional story problem types.

In Unit 3, Measurement, students build on their kindergarten experiences with describing and comparing measurable attributes as they deepen their understanding of length by comparing objects both directly and indirectly. They learn to measure by iterating length units and recognizing that a measurement tells how many equal units span an object. Students develop the understanding that length can be described and compared using a number of same-size units. Students solve new compare type story problems in the context of measurement. This unit strengthens reasoning about measurement and units, providing a foundation for later work with standard units of measure, measurement tools, and number lines.

In Unit 4, Adding and Subtracting Within 20, students extend addition and subtraction beyond 10 as they begin solving problems within 20. Students apply their understanding of composing and decomposing numbers to develop efficient strategies, including: making a ten, using the relationship between addition and subtraction, and using known facts like doubles and near doubles, for computation and to solve problems. Students continue to use a variety of tools and representations to support their thinking. They also solve familiar story problem types within 20, and are introduced to start unknown problem types. The work in this unit prepares students to work with place value and addition within 100 in later units.

In Unit 5, Data Investigations, students build on their understanding of classification as they begin to organize, represent, and interpret categorical data. They collect and represent data in up to three categories using tools such as linking cubes, drawings, data tables, and tallies. Students ask and answer questions about data and apply their understanding of addition and subtraction within 20 to solve problems in the context of data. They are also introduced to new compare problem types in which students determine the bigger or smaller quantity, strengthening reasoning about relationships between quantities. The unit shows how data can be used to answer questions and tell a story, while preparing students to represent and interpret data with picture graphs and bar graphs in 2nd grade.

In Unit 6, Place Value to 99, students build on their earlier work with composing and decomposing numbers and understanding ten as a unit as they develop an understanding of two-digit numbers as groups of tens and ones. They count, read, and write numbers up to 120 and represent quantities with written numerals. Using tools such as linking cubes, tiny ten frames, and drawings, students compose and decompose numbers and make sense of the base ten structure of our number system. Through activities like counting collections, students organize objects into groups and begin to see the efficiency of grouping by tens. They also compare two-digit numbers by reasoning about the number of tens and ones in each number and record their comparisons using the symbols >, <, and =. This work provides a foundation for addition and subtraction with two-digit numbers in Unit 7 and prepares students for more advanced place value concepts in 2nd grade.

In Unit 7, Adding with Place Value Within 100, students use their understanding of tens and ones to develop strategies for adding within 100. They reason about how numbers change when tens and ones are added and use place value to make sense of sums. Students explore patterns in the base ten system by adding multiples of ten, adding tens and ones, and composing new tens when needed. They represent their thinking with concrete models, drawings, and equations and compare strategies such as combining tens and ones or counting on by tens and then ones. These experiences help students see that addition within 100 can be understood by reasoning about tens and ones. The unit prepares students for the 2nd grade expectation of fluently adding and subtracting within 100.

Finally, in Unit 8, Shapes and Time, students explore geometry and time as they sort, classify, and compose two- and three-dimensional shapes based on defining attributes such as sides and corners. They partition circles and rectangles into 2 and 4 equal shares, connecting these ideas to halves and fourths. Students also tell and write time to the hour and half hour using analog and digital clocks, linking half hours to partitioned circles. This unit builds foundational understanding of shapes, equal shares, and time, preparing students for later work with geometry, fractions, and time.