Multiplication Using Arrays
This is a lesson plan created by Jennifer Payne. It is meant to enhance student learning and supports 4th Grade Utah State Math Standards 4.OA.4 and 4.MP.4.
In this lesson, students will develop an understanding of multiplication concepts using visual representations of the multiplication process. Students will learn that an arrangement of objects, pictures, or numbers in columns and rows is called an array. Arrays are useful representations of multiplication concepts.
- Time frame: 60-90 minutes or two 45 minutes sessions
- Group size - Whole Group
Background for Teachers
To teach this lesson, you will need and understanding of arrays. An array is a way to represent multiplication and division using rows and columns. Rows represent the number of groups. Columns represent the number in each group or the size of each group. For example, students can picture a marching band arranged in equal rows or chairs set up in rows in an auditorium.
Student Prior Knowledge
- Prior to this lesson, students will need to have an understanding of the meaning of the words factors (a number that you multiply with another number to get a product), multiples (what you get after multiplying a number by an integer), and product (the answer to a multiplication problem).
- Students will need to be familiar with using computers and iPads.
- The students will need to have prior knowledgeable of the importance of citing photos and information that is not their own work, along with how to properly cite the work. Students also need to be familiar with safe searches and finding pictures that are not copyrighted. Possible site students could use to create their citations: EasyBib
- Adobe Spark will be used as a final project, therefore students need to be versed in how to use the program.
Student Learning Intentions & Success Criteria
- Students will be able to create arrays in order to determine the product of two factors.
- Students will be able to recognize arrays that they see in the world around them.
- Ipads for each student
- Index Cards
- Adobe Spark
- Counters for each student
- Adobe Spark Example
- Introduce the word "array" on the white board. Explain that an array is a picture, set of objects, or symbols that are displayed in rows and columns to represent a multiplication problem.
- With a document camera, use counters to show students several examples of arrays. Next, distribute the counters to the students. Write some multiplication facts on the board such as 3 x 4 (3 rows of 4 counters) and 5 x 4 (5 rows of 4 counters) and have them each try making some arrays on their own with the counters. Remind the students that the total number of counters in each array is the product of the two numbers being used. Have students explain their arrays to a partner.
- Tell the students that we are now going on an array hunt through the school building. Have students take their iPads as they explore the building and take photographs of any arrays that they see.
- When the class has returned to the classroom, have the students share their photos with the rest of the class. Discuss each array. (If the student's pictures do not show an accurate ray, discuss why and reinforce what an array should represent.)
- Explain to the students that they are now going to create a project using Adobe Spark to show their knowledge of arrays. Their presentation needs to contain at least 5 pictures showing different arrays that they would find in the real world. The students also need to include a slide that where they have cited any images they have used from the internet. Students can use the pictures they took during their exploration of the school, and/or they can use Google Images or images on Adobe Spark. Each slide must show the multiplication problem that the array represents. Show the students the Adobe Spark example (which also includes what a citation should look like) before they get started so they have an idea of what is expected.
- When everyone has their Adobe Sparks completed, share presentations with the entire class.
Think-Pair-Share - Have students turn to a partner and discuss the following question: How would an array be useful to solve for an unknown factor? i.e. 5 x n = 25
Strategies for Diverse Learners
In this lesson, manipulatives are used to support visual and kinesthetic learners. There are also activities provided where ELL students and students with disabilities have the opportunity to receive reinforcement from their peers during group activities and Think-Pair-Shares.
Exit Ticket: Give each student an index card. Write the following word problem on the board: There are 5 rows of desks. Each row has 6 desks. How many desks are there? Have the students solve the problem on the index card. Tell the student that they must show their work using and array as wll as the the product on their card.