3.MD.C.7b: Finding Area

Evidence Statement 3.C.3-2 Base explanations/reasoning on concrete referents such as diagrams (whether provided in the prompt or constructed by the student in their response), connecting the diagrams to a written (symbolic) method.

Madison's Garden

Madison is getting ready to plant her garden for the season. 

• She is planting three vegetables and two sections with cut flowers for bouquets. 
• The garden has a width of 30 feet. 
• The length of the section where corn is going to be planted is two times the width of that section.

The garden shows five different rectangular sections where items are planted. The carrot section is 6 feet long and 20 feet wide. The cut flower section is 4 feet long and 20 feet wide The tomato section is 10 feet long and 20 feet wide. The length of the cut flower section is 5 feet long and 30 feet wide. The length off the corn section is 20 feet long and 10 feet wide.

What is the area of each section of the garden?

• What is the area of the section where corn is going to be planted? 

• What is the area of the section where tomatoes are going to be planted? 

• What is the area of the section where carrots are going to be planted? 

• What is the total area of the garden? 

Enter your work and your answers in the space provided. 

Student Copy

Scoring Rubric

Score of 4

Student response includes the following 4 elements.

• The area of the section where corn is going to be planted with supporting work.

• The area of the section where tomatoes are going to be planted with supporting work.

• The area of the section where carrots are going to be planted with supporting work.

• The total area of the garden with supporting work.

Sample Student Response:

The area of the corn section is 200 square feet. 2 x 10 = 20 feet which is the length of the section where corn is planted. 20 x 10 = 200 square feet.

The area of the tomato section is 200 square feet. 10 x 20 = 200 square feet.

The area of the carrot section is 120 square feet. 6 x 20 = 120 square feet.

The area of the total garden is 120 + 80 + 200 + 150 + 200 = 750 square feet.

Note: When labels are not presented, the elements are scores in the same order as the prompt. The corn section is addressed first, the tomato section next, the carrot section third, and the total area of the garden is last.

Note: Students do not need to multiply length times width to find the total area of the garden. The area of the garden can be found by adding up the area of each section of the garden.

Score of 3

Student response includes 3 of the 4 elements.

Score of 2

Student response includes 2 of the 4 elements.

Score of 1

Student response includes 1 of the 4 elements.

Score of 0

Student response is incorrect or irrelevant.