Multiply/Divide with Arrays
TEACHERS:Desjadon / SUBJECT:
Math
STANDARD:
· 3.OA.3. Use multiplication and division within 100 to solve word problems in situations involving equal groups, arrays, and measurement quantities
OBJECTIVE (EXPLICIT):
· Students will use arrays to demonstrate an understanding of equal groups (or repeated addition) as multiplication/division.
EVIDENCE OF MASTERY (MEASURABLE):
Students will generate arrays to solve real world situations (word problems using equal groups, including measurement quantities).
SUB-OBJECTIVES, SWBAT (SEQUENCED FROM BASIC TO COMPLEX):
· Create an array for a given multiplication fact.
· Write a multiplication fact for a given array picture.
· Create an array and an equation, explaining why the arrangement fits the equation.
· Determine if an equation fits the displayed array.
KEY VOCABULARY:
Array
Repeated addition
Rows
Columns / MATERIALS:
1” color tiles (40 per group)
Deck of playing cards sorted by color (one per group)
Graph paper (1 sheet per student)
pencil (1 per student)
ENGAGE (MAKE CONTENT AND LEARNING RELEVANT TO REAL LIFE AND CONNECT TO STUDENT INTEREST)
BEFORE / TEACHER WILL:
Introduce the problem: “Mr. King is planting a garden. He has 9 rows. He has space to plant 4 plants in each row. How many plants does Mr. King have room to grow in his garden?” (Emphasize the rows and columns terminology).
*How can we use the tiles to solve the problem?
*Introduce “Array” --- Kinesthetically lead students to touch and repeat | rows -- columns. How many rows? How many columns? How many all together?
*Model activity with 2 students --- deck of cards sorted by color. Red card will indicate number of rows, Black card will tell number of columns. One student has red cards, other student has black cards. Each student flips one card --- Using their tiles, generate the array model. Discuss and compare. Draw the agreed array model on their paper, labeling rows/columns/total. / STUDENT WILL:
*Use the tiles to create a representation of Mr. King’s garden on their desktop. (individual)
* Pair-Share to compare the array models set up on desk.
*Observe the modeled activity.
*Ask clarifying questions.
CO-TEACHING STRATEGY IF APPLICABLE
DURING / TEACHER WILL:
*Monitor student partners working on activity.
*Ask probing questions if misconception is visible in small group:
--- What does the red card represent?
--- Which directions do the ‘rows’ go?
--- What does the black card tell us?
--- If I ask you about “column”, what does that
mean?
*Prompt challenge for groups with firm understanding to push the idea:
--- Could we find the number of rows if we know
the columns and the total number used?
--- Could you create a real life situation where this
could be helpful? / STUDENT WILL:
*Work in partners, using cards and paper, to create arrays.
*Flip one red, one black card to determine rows and columns.
*Draw and lable the dictated array.
*Compare and discuss with partner.
*Continue with additional cards until the time is up.
CO-TEACHING STRATEGY IF APPLICABLE
AFTER / TEACHER WILL:
*Refocus class to whole group.
*Ask students to show kinesthetic movements of rows (|) and columns (-)
*Revisit and solve problem: “Mr. King is planting a garden. He has 9 rows. He has space to plant 4 plants in each row. How many plants does Mr. King have room to grow in his garden?”
*Display an array and a set of numbers. Ask students if the numbers accurately fit the array.
*Ask student definitions for key vocabulary. / STUDENT WILL:
*Quick clean up, and return to whole group.
*Kinesthetically show up and down motion for rows and side to side for columns when directed.
*Discuss with partner to answer original problem, proving answer with drawn models.
*Provide explinations to prove or disprove the fit of the “rows” and “columns” for the displayed array and cards.
*Use knowledge from activity to define vocabulary.
CO-TEACHING STRATEGY IF APPLICABLE