3.MD.C.7b Modeling A Rectilinear Figure Problem

Evidence Statement- 3.D.1 Solve multi-step contextual word problems with degree of difficulty appropriate to Grade 3, requiring application of knowledge and skills articulated in Type 1 Evidence Statements.

The Paz Family Garden

The Paz family is building a garden in their backyard.  The two plans they are choosing between are shown below. They want to build the garden with the largest area.

Part A

• What is the total area, in square feet, of Garden Plan A? 
• Write an equation or equations to represent the total are of Garden A.

Enter your equation or equations in the space provided.

Part B

What is the total area, in square feet of Garden Plan B? 

• Write an equation or equations to represent the total area of Garden B.

Enter your equation or equations in the space provided.   

Part C

Which garden plan should the Paz family choose? Explain your answer using < or >.

Enter your  answer and explanation in the space provided.

Student Copy

Scoring Rubric Part A

Score 4

Student response includes the following elements.

Computation Component

• The student provides the correct areas for the smaller rectangles.
• The student provides the correct total area for Garden Plan A.

Modeling Component

• Valid method to determine the areas of the smaller rectangles.
• Valid method to determine the total area of Garden Plan A. 

Sample Student Response:

9x6=54

6x4=24

6x10=60

54+24+60=138

The total area of Garden Plan A is 138 square feet.

Score 3

Student response includes three of the elements.

Score 2

Student response includes two of the elements.

Score 1

Student response includes one of the elements.

Score 0

Student response is incorrect. 

Scoring Rubric Part B

Score 4

Student response includes the following elements.

Computation Component

• The student provides the correct areas for the smaller rectangles.
• The student provides the correct total area for Garden Plan B.

Modeling Component

• Valid method to determine the areas of the smaller rectangles.
• Valid method to determine the total area of Garden Plan B.

Sample Student Response:

6x10=60

5x7=35

4x4=16

60+35+16=111

The total area of Garden Plan B is 111 square feet.

Score 3

Student response includes three of the elements.

Score 2

Student response includes two of the elements.

Score 1

Student response includes one of the elements.

Score 0

Student response is incorrect.

Scoring Rubric Part C

Student response includes the following element.

Computation Component

• Student identifies 138 as being the larger area.

Sample Student Response:

The Paz family should choose Garden Plan A because 138>111.