Problem Solving
How do you use what you have learned to problem solve?
Goal:
Goal:
Practice!
Goal: Apply what you have learned about finding area and total cost to solve a word problem.
Remember, when you want to find the cost of something that relates to the area, first find the area and then multiply by the unit cost.
1 unit by 1 unit equals 1 square unit. \({\times }\) cost per square unit equals total cost of area.
Let’s practice finding the cost of the area of something. Remember to use these problem-solving steps to help you find the answers to word problems.
Word Problem Solving Steps
- Read the problem.
- Look for important information.
- Write a math sentence.
- Choose a way to solve.
- Solve and label your answer.
Solve for the area and total cost.
Tom is building a square sandbox in his yard that measures 4 feet on one side. The cost of sand is $5 per square foot. What is the total cost of the sand in the sandbox?
That is right! 4 ft \({\times}\) 4 ft \({=}\) 16 ft\({^2}\) \({\times}\) $5 \({=}\) $80
Sorry, that is incorrect. Remember to find the area and then multiply by the unit cost to find the total cost.
Solve for the area and total cost.
Khloe wants to sell her playhouse. The house costs $11 per square unit. If the playhouse is 10 units by 7 units, what is the area of the house and the cost?
That is right! 10 units \({\times}\) 7 units \({=}\) 70 square units \({\times}\) $11 \({=}\) $770
Sorry, that is incorrect. Remember to find the area and then multiply by the unit cost to find the total cost.
Solve for the area and total cost.
Jennifer is planting sunflower plants in her garden. If the plot of land is 3 km by 4 km and the cost of sunflower plants is $7 per km\({^2}\), what is the area of the plot and the cost of the plants?
That is right! 3 km \({\times}\) 4 km \({=}\) 12 km\({^2}\) \({\times}\) $7 \({=}\) $84!
Sorry, that is incorrect. Remember to find the area and then multiply by the unit cost to find the total cost.
Solve for the area and total cost.
Melissa wants to frost a cake for her birthday. The cake is 9 inches by 9 inches, and the frosting is $1 per square inch. What is the area of the cake and the cost of the frosting?
That is right! 9 in. \({\times}\) 9 in. \({=}\) 81 in\({^2}\) \({\times}\) $1 \({=}\) $81.
Sorry, that is incorrect. Remember to find the area and then multiply by the unit cost to find the total cost.
Solve for the area and total cost.
Zoe is covering her wall with wallpaper. The wall is 8 feet by 9 feet, and the paper costs $6 per square foot. What is the area of the wall being covered and the cost?
That is right! 8 ft \({\times}\) 9 ft \({=}\) 72 ft\({^2}\) \({\times}\) $6 \({=}\) $432!
multiply by the unit cost to find the total cost. Use the distributive property to help you multiply the total area by the cost.
Great Job!