Area and Perimeter (Advanced) — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
A square has a side of 6 units, so its area is 6 plus 6, which equals 12 square units.
Corrected: A square has a side of 6 units, so its area is 6 times 6, which equals 36 square units.
Area equals side multiplied by side, so 6 x 6 gives 36 square units, not 12.
2. Fix the sentence:
The area of a square with side 9 inches are 81 square inches because 9 times 9.
Corrected: The area of a square with side 9 inches is 81 square inches because 9 times 9 equals 81.
Area is one measurement, so the singular verb is matches the singular noun area in Grade 4 writing.
3. Fix the sentence:
Each side of the tile measure 5 cm, so the total area is 25 square centimeters.
Corrected: Each side of the tile measures 5 cm, so the total area is 25 square centimeters.
Each side acts as a singular subject, so the verb measures takes an s in the present tense.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. A square with a side of 6 units has an area of 36 square units.
Side times side gives 6 x 6 = 36, so the square covers 36 square units.
2. The shortcut for the area of a square is side times side.
Because all four sides are equal, area = side x side, a quick square-only shortcut.
3. A square tile has a side of 8 cm, so its area is 64 square centimeters.
Using side x side, 8 x 8 equals 64, so the tile covers 64 square centimeters.
4. Area is always measured in square units, not in regular length units.
Length uses units, but area covers two dimensions, so we label it square units.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Explain why the area of a square with side 7 units is 49 square units.
Sample answer: A square has four equal sides, so I use side times side. Multiplying 7 by 7 gives 49, so the area is 49 square units. This shortcut works only because every side of a square is the same length.
The square shortcut works for Grade 4 because equal sides let one number stand for both length and width.
2. How is finding the area of a square different from finding the perimeter of a square?
Sample answer: For area, I multiply side by side to cover the surface in square units. For perimeter, I add all four sides or multiply one side by 4 to find the distance around. Area uses multiplication for square units, while perimeter uses addition for length units.
Area measures inside space in square units; perimeter measures the outside path in length units.