# Arranging Chairs

TASK: Students were asked to arrange 12 tiles into straight rows for an audience to watch a play  Click for the instructional ppt Rolling Valley GMU Lesson_study_Ppt

SOL 3.6 Students will represent  multiplication and division using area models and sets, and number line models, and create and solve problems that involve multiplication of two whole numbers, one factor 99 or less and the second factor five or less.

Goals:

• Commutative Property – to recognize a x b = b x a and a + b = b + a (foundation for commutative property)
• Introduce to rectangular arrays
• These concepts will be the foundation for learning about area, multiplication, multiple arrays (factors)

Previous Knowledge

1. Skip counting
3. Vocabulary – row, column, rectangle, array

SOL 3.6 Students will represent multiplication and division using area models and sets, and number line models, and create and solve problems that involve multiplication of two whole numbers, one factor 99 or less and the second factor five or less.

Anticipate:

Methods:
Count by ones, Count by twos
Count by fours, Count by threes
Students may not come up with 2 orientations of each array
Students will come up with 1 x 12 and then split apart.
Some students may know all the factors already and make the arrays and multiplication statements.

Misconceptions:  Not making even rows, not keeping a rectangle, not understanding that a square is a rectangle.

Errors:    Making uneven rows, and using incorrect numbers of tiles to make arrays.  Not able to draw the representation on recording sheet, not coming up with all arrays that are possible for the number, labeling arrays incorrectly.  Students making array with tiles, but not copying the array on the paper.

Resources:  12 inch tiles for each pair of students, inch graph paper for each pair, and pencils and erasers.

Students will work in pairs.  The students will be paired by varying ability levels; most students will be paired heterogeneously making sure that low IEP/ESOL students will have support with similar ability levels.

Recording/reporting:  Showing array using tiles, drawing arrays on graph paper, students will label the dimensions on drawings.

Use smartboard to share student ideas with entire class.

Extension – 16 tiles for early finishers to try various arrays; 4 additional tiles for a total of 20 tiles during self-selecting time.