Math by Topic Sampler

Lesson Plan for Student Book BII, Page 7 O BJECTIVE : To build an array as a model of a multiplication fact. M ATERIALS : Interlocking cubes, 1-inch graph paper (Master 10), ruler, stapler, scissors V OCABULARY : Array I NTRODUCTORY A CTIVITIES Building Arrays and Drawing Pictures Students may work in pairs or small groups. Make a set of 3 cubes. How many groups of 3 do you have? (1) How many cubes in all? (3) Write the fact. (1 x 3 = 3) Now make a set of 3 cubes of one color. Review the number line model for multiplication by placing 2 groups of 3 on the number line to show the landing point of 6. Write the multiplication sentence. (2 x 3 = 6) Now we will learn another type of model. Put your cubes on top of each other to form a rectangle. How many groups or rows of 3 do you have? (2) How many cubes in all? (6) Write the multiplication fact. (2 x 3 = 6) Repeat this procedure through 9 groups of 3. We have just made models called “arrays” of the multiplication facts for the 3s. We call these pictures “arrays.” An array is a rectangle. The sides of the rectangle are the numbers being multiplied. The answer is equal to the number of small squares inside the array. We will draw pictures of each of the arrays in the threes family on graph paper. Outline an array to show 1 group of 3. The array will look like 1 row of square cubes. Write 1 x 3 on your array. Repeat through 9 groups of 3. Have each student cut out their nine arrays and staple them at the top to make a stair of 3s. The answer to each fact is written on the back of the array so that the student can use the stairs to drill and check on the multiplication facts with the 3s. Make twos, fours, and fives from graph paper. 1 x 3 1 1 2 3 A BOUT T HIS P AGE F OLLOW U P A CTIVITIES Skill Builders 20-2 Student Book 4 x 3 3 x 3 2 x 3 1 2 3 4 5 6 7 8 9 1 2 3 1 x 3 2 x 3 3 x 3 4 x 3 5 x 3 6 x 3 7 x 3 8 x 3 9 x 3 Staple all strips at the top. 1 x 3 Put the larger arrays in back of the smaller ones. Write the answers on the back of each Answer Key 1. 15 2. 20 3. 30 4. 35 5. 8 6. 14 7. 18 8. 12 9. 2 x 4 = 8 10. 2 x 6 = 12 11-12. Follow directions . 30 L E V E L B g r a d e s 3 – 4 Explicit, Conceptually-Based Instruction: build an array of a multiplication fact * Not all lessons follow this format Reinforce 3 Introduce > Explore 1 Visualize 2 Level B Teachers Manual 7