Before You Begin this Unit…  
Unit at a Glance 
This unit builds on the ideas about patterns and sequences from first grade. Students in first grade constructed, described and extended repeating patterns using connecting cubes and body movement patterns. They also identified the pattern unit (the part that repeats) and compared how repeating patterns can be alike and different. This idea of comparing situations in different contexts will continue in this unit, as students explain how different ratio situations can result in the same table (Investigation 1). Students in first grade also worked with patterns that have a constant increase. By this point in second grade, students should be familiar with counting by specific numbers (2’s, 5’s and 10’s), as seen in Unit 3 (Stickers, Number Strings and Story Problems). For this unit, students do not need to know all counting sequences (counting by 3’s, etc.) because they can engage in this work by counting or adding. Students also need to be familiar with situations in which they encounter equal groups (2 shoes in a pair, 5 fingers on a hand, etc.). In this unit, they will begin to think about how ratios can be expressed in many pairs of numbers (5 fingers on one hand, so there are 20 fingers on 4 hands). They will explore these ratio situations with cube buildings and pattern blocks; and record data in a table as they begin to notice how different situations can have the same relationship between quantities. 
Suggested Dates: January 20February 9Estimated Duration: 12 days 

Standards Addressed in the Unit  
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.OA.3 Determine whether a group of objects (up to 20) has an odd or even number of members, e.g., by pairing objects or counting them by 2s; write an equation to express an even number as a sum of two equal addends. 2.OA.4 Use addition to find the total number of objects arranged in rectangular arrays with up to 5 rows and up to 5 columns; write an equation to express the total as a sum of equal addends. 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. 2.G.2 Partition a rectangle into rows and columns of samesize squares and count to find the total number of them. Link to CCSS Unpacking Document 