Before You Begin this Unit…  
Unit at a Glance 
This unit builds on the work of Units 1 and 3. In those units, students focused on counting in groups, composing numbers and the operations of addition and subtraction. Students also engaged in the work of place value and the number system, using stickers as a way to model numbers in base ten. In this unit, students will continue to explore place value concepts with an emphasis on the structure of 100. They will also refine their strategies for adding and subtracting 2digit numbers by breaking apart by place and by keeping one number whole. To show their thinking, students will use tools such as number lines, hundred charts, coins, and baseten sticker notation. Students will also revisit the work they did in Unit 5 by identifying patterns when equal groups are added. They will count by groups of 2s, 5s and 10s, recognizing the patterns that exist in those sequences. This work lays the foundation for students’ work with 100 and how it is composed of equal groups. Students will approach 100 as a number composed of groups of tens and ones, and a number composed of equal groups of 2s, 5s and 10s. They will also approach 100 as combinations of coins that create one dollar. 
Suggested Dates: Estimated Duration: 25 days 

Standards Addressed in the Unit  
2.OA.1 Use addition and subtraction within 100 to solve one and twostep word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem 2.OA.2 Fluently add and subtract within 20 using mental strategies.^{2} By end of Grade 2, know from memory all sums of two onedigit numbers. 2.NBT.1 Understand that the three digits of a threedigit number represent amounts of hundreds, tens, and ones; e.g., 706 equals 7 hundreds, 0 tens, and 6 ones. 2.NBT.2 Count within 1000; skipcount by 5s, 10s, and 100s. 2.NBT.3 Read and write numbers to 1000 using baseten numerals, number names, and expanded form. 2.NBT.5 Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction. 2.MD.7 Tell and write time from analog and digital clocks to the nearest five minutes, using a.m. and p.m. 2.MD.8 Solve word problems involving dollar bills, quarters, dimes, nickels, and pennies, using $and ¢ symbols appropriately. 2.G.1 Recognize and draw shapes having specified attributes, such as a given number of angles or a given number of equal faces.^{1} Identify triangles, quadrilaterals, pentagons, hexagons, and cubes.
Link to CCSS Unpacking Document 