OVERVIEW In this unit students will: • Understand and model multiplication as repeated addition and as rectangular arrays. • Determine if a number is odd or even (within twenty). • Create and interpret picture graphs and bar graphs. STANDARDS FOR MATHEMATICAL CONTENT Work with equal groups of objects to gain foundations for multiplication. MGSE2.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. MGSE2.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 Represent and interpret data. MGSE2.MD.10. Draw a picture graph and a bar graph (with single-unit scale) to represent a data set with up to four categories. Solve simple put-together, take-apart, and compare problems using information presented in a bar graph.
BIG IDEAS By the conclusion of this unit, students should be able to demonstrate the following competencies: • Understand the similarities between skip counting, repeated addition, and multiplication. • Construct arrays for a given repeated addition sentence. • Write a repeated addition equation for a given array. • Determine how the addition sentence for a given array changes when the array is rotated ¼ turn. • Understand that multiplication is repeated addition. • Write an equation to express an even number. • Identify if a number is even or odd by modeling the number in pairs. • Draw and interpret a picture and a bar graph to represent a data set with up to four categories. • Repeatedly adding the same quantity, using a grouping picture or forming a rectangular array are strategies for representing repeated addition equations. • Arrays are a way of representing both repeated addition and skip counting. • Arrays should be identified in rows and then columns. • Explore and be able to explain even and odd numbers while using manipulatives. • An even number can be decomposed into two equal addends. • Double addition facts assist in recognizing even numbers. • Tables and charts can help make solving problems easier. • Questions can be solved by collecting and interpreting data.