- Using concrete objects (linking cubes, color tiles, food, etc.), build a rectangular array with 2 rows and 5 columns.
- Ask students to think about the objects and what they see. Have students talk with a shoulder partner to answer questions such as: "How many objects do you see?", "How many rows?", "How many columns?", "How many objects are in each row or column?"
- Have a few students share their conversations by answering the questions discussed with his/her partner.
- Remind students that objects in rows and columns are called "arrays".
- To make the connection from the concrete array to pictorial, build the 2 x 5 array using the Interactive Tens Frame/Work Mat resource.
- Use the following steps to change the number of rows and/or columns on the work mat:
- Click on the "rows" dropdown menu. Change to 5.
- Click on the "columns" dropdown menu. Change to 5.
- Choose a color, then click the "fill" button to fill in the array.
- The teacher will show students how to represent the objects using a repeated addition sentence. Ex. 5 + 5 = 10, 2 + 2 + 2 + 2 + 2 = 10.
- Repeat steps 1 through 6, using different combinations of rows and columns (up to 5.)
- Give students the equation 2 + 2 + 2 and have them represent the array in a drawing.
- The teacher will show what the drawing should look like using the Interactive Tens Frame/Array Work Mat.
- Allow students to compare and share drawings. Repeat with other equations.
Students will draw an array to match the following repeated addition equations. The teacher will perform a quick assessment of drawings through observation to determine the next instructional steps or continue to mastery assessment.
- 3 + 3 + 3 = 9
- 4 + 4 + 4 + 4 = 12
Students will write an equation to match the following arrays (displayed by the teacher using a drawing or Interactive Tens Frame/Work Mat.) The teacher will assess students' understanding through observation to determine the next instructional steps or continue to mastery assessment.
- 5 rows and 4 columns
- 3 rows, 2 columns
Students will complete the following for the assessment of mastery.
Arrays Repeated Addition Assessment
Become familiar with the Interactive Tens Frame/Arrays Work Mat. You can change the grid to format a 5 x 5 work mat, suitable for the content standard. (Instructions are included in the activity section)
Gather the concrete items needed to build arrays.
Prepare the assessment equations and arrays. Print and copy the assessment handout.
|Variation Tips (optional):
Some students may need to use concrete representations longer than others. It is important not to go straight to pictures before students are ready.
Allow students to explore/locate arrays outside the classroom, or as a homework activity.
|Notes or Recommendations (optional):
4. Using concrete and pictorial representations and repeated addition, determine the total number of objects in a rectangular array with up to 5 rows and up to 5 columns.
a. Write the equation to express the total number of objects in a rectangular array with up to 5 rows and up to 5 columns as a sum of equal addends. (2OA.4)