Let’s Practice!
Which strategy is used to solve for area and cost of a rectangular shape?
Goal:
Goal:
You Can Do It!
Goal: Solve area word problems by decomposing a rectangle.
Remember, when you are trying to find the total area of something, you break it apart into smaller rectangular shapes. Then, you find the area of each part of the figure and add the sections together to get the total area. To find the total cost, you multiply the total area by the unit cost.
An area the left width is 5 inches the top lenght is 8 inches. The right sections width is 2 inches and its length is 3 inches.
\({5\;in \times 5\;in = 25\;in^2}\)
\({3\;in \times 2\;in = 6\;in^2}\)
\({25\;in^2 + 6\;in^2 = 31\;in^2}\)
Total area \({\times}\) cost per square unit \({=}\) Total cost of area.
31 in\({^2 \times}\) $2 per square inch \({=}\) $62
For each problem below, find the total area and cost of the figure. Look at each slide and click on the image to check your work.
An area. The first section is 3 units wide and 7 units in length. The second section is 3 units in width and 6 units in lenght. The cost is 4 dollars per square unit.
6 units \({\times}\) 3 units \({=}\) 18 square units,
7 units \({\times}\) 3 units \({=}\) 21 square units,
18 square units \({+}\) 21 square units \({=}\) 39 square units,
39 square units \({\times}\) $4 \({=}\) $156
An area with two sections. The first sections width is 5 centimeters, and the length is 3 centimeters. The second section is 7 centimeters in width and 6 centimeters in length. The total length of both sections is 9 centimeters. The cost is is 2 dollar per square centimeters.
5 cm \({\times}\) 3 cm \({=}\) 15 cm\({^2}\),
7 cm \({\times}\) 6 cm \({=}\) 42 cm\({^2}\),
15 cm\({^2}\) \({+}\) 42 cm\({^2}\) \({=}\) 57 cm\({^2}\),
57 cm\({^2}\) \({\times}\) $2 \({=}\) $114
An area. The area has sections. The first section has a width of 5 units and a length 6 units. The second section has a width of 5 units and a lenght of 4 units. The cost is 5 dollars per square unit.
\({5 \times (6 + 4) = (5 \times 6) + (5 \times 4) = 30 + 20 = 50}\) square units \({\times}\) $5 per square unit \({=}\) $250
You know your multiplication facts and how to solve for area and cost. Find the area of the figures using decomposition.
What is the total area?
- 48 square units
- 52 square units
- 64 square units
- 4 square units
Remember to break apart the shape into smaller sections, find the area of each section, then add the different areas together.
Correct! The total area is 52 square units.
Remember to break apart the shape into smaller sections, find the area of each section, then add the different areas together.
Remember to break apart the shape into smaller sections, find the area of each section, then add the different areas together.
What is the total cost?
- $100
- $200
- $152
- $76
Remember to break apart the shape into smaller sections, find the area of each section, then add the different areas together. Finally multiply that value by the unit cost to find the total cost
Remember to break apart the shape into smaller sections, find the area of each section, then add the different areas together. Finally multiply that value by the unit cost to find the total cost
Correct! The total cost is $152.
Remember to break apart the shape into smaller sections, find the area of each section, then add the different areas together. Finally multiply that value by the unit cost to find the total cost
What is the total area?
- 66 square units
- 42 square units
- 24 square units
- 330 square units
Correct! The total area is 66 square units.
Remember to break apart the shape into smaller sections, find the area of each section, then add the different areas together.
Remember to break apart the shape into smaller sections, find the area of each section, then add the different areas together.
Remember to break apart the shape into smaller sections, find the area of each section, then add the different areas together.
Summary
Questions answered correctly:
Questions answered incorrectly: