Section A Section A Checkpoint

Problem 1

Write a multiplication expression that represents the area of the shaded region. Explain or show your reasoning.

Diagram. Square, length and width, 1. Partitioned into 3 rows of 8 of the same size rectangles. 1 rectangle shaded.

Show Solution
Solution
13×18\frac{1}{3} \times \frac{1}{8} or 18×13\frac{1}{8} \times \frac{1}{3}. Sample response: 13\frac{1}{3} of 18\frac{1}{8} of the square is shaded. So, that's 13×18\frac{1}{3} \times \frac{1}{8}.
Show Sample Response
Sample Response
13×18\frac{1}{3} \times \frac{1}{8} or 18×13\frac{1}{8} \times \frac{1}{3}. Sample response: 13\frac{1}{3} of 18\frac{1}{8} of the square is shaded. So, that's 13×18\frac{1}{3} \times \frac{1}{8}.

Problem 2

Find the value of each expression. Draw a diagram if needed.

  1. 14×15\frac{1}{4} \times \frac{1}{5}
  2. 23×34\frac{2}{3} \times \frac{3}{4}
  3. 54×56\frac{5}{4} \times \frac{5}{6}
Show Solution
Solution
  1. 120\frac{1}{20}

    Diagram

  2. 612\frac{6}{12} or 12\frac{1}{2}

    Diagram.

  3. 2524\frac{25}{24} or 11241\frac{1}{24}

    Diagram

Show Sample Response
Sample Response
  1. 120\frac{1}{20}

    Diagram

  2. 612\frac{6}{12} or 12\frac{1}{2}

    Diagram.

  3. 2524\frac{25}{24} or 11241\frac{1}{24}

    Diagram

Problem 3

A rectangular garden is 2122\frac{1}{2} meters wide and 4124\frac{1}{2} meters long. What is the area of the garden? Explain or show your reasoning.

Show Solution
Solution

111411\frac{1}{4} square meters (or equivalent). Sample response: 2×2122 \times 2\frac{1}{2} is 5 so  4×212=104 \times 2\frac{1}{2} = 10. Then 12×2=1\frac{1}{2} \times 2 = 1 and 12×12=14\frac{1}{2} \times \frac{1}{2} = \frac{1}{4}. So, that’s 10+1+1410 + 1 + \frac{1}{4} or 111411\frac{1}{4} square meters.

Show Sample Response
Sample Response

111411\frac{1}{4} square meters (or equivalent). Sample response: 2×2122 \times 2\frac{1}{2} is 5 so  4×212=104 \times 2\frac{1}{2} = 10. Then 12×2=1\frac{1}{2} \times 2 = 1 and 12×12=14\frac{1}{2} \times \frac{1}{2} = \frac{1}{4}. So, that’s 10+1+1410 + 1 + \frac{1}{4} or 111411\frac{1}{4} square meters.