Calculate Rectangle Area: 2½ m × 3¼ m Mixed Number Multiplication

Question

What is the area of a rectangle with a length of 212 2\frac{1}{2} m and a width of314 3\frac{1}{4} m?

Video Solution

Step-by-Step Solution

To find the area of a rectangle when given the dimensions as mixed numbers, follow these steps:

  • Step 1: Convert each mixed number to an improper fraction.
  • Step 2: Multiply the two fractions to find the area.
  • Step 3: Simplify the resulting fraction, if necessary, back to a mixed number.

Step 1: Convert the mixed numbers to improper fractions.

The length is 2122\frac{1}{2} meters. To convert 2122\frac{1}{2} to an improper fraction:

  • Multiply the whole number (2) by the denominator of the fractional part (2): 2×2=42 \times 2 = 4.
  • Add this result to the numerator of the fractional part (1): 4+1=54 + 1 = 5.
  • The improper fraction is 52\frac{5}{2}.

The width is 3143\frac{1}{4} meters. To convert 3143\frac{1}{4} to an improper fraction:

  • Multiply the whole number (3) by the denominator of the fractional part (4): 3×4=123 \times 4 = 12.
  • Add this result to the numerator of the fractional part (1): 12+1=1312 + 1 = 13.
  • The improper fraction is 134\frac{13}{4}.

Step 2: Multiply the two improper fractions.

Area=52×134=5×132×4=658\text{Area} = \frac{5}{2} \times \frac{13}{4} = \frac{5 \times 13}{2 \times 4} = \frac{65}{8}.

Step 3: Simplify 658\frac{65}{8} to a mixed number.

  • The quotient of 65÷865 \div 8 gives 8 as the whole number.
  • The remainder is 65(8×8)=6564=165 - (8 \times 8) = 65 - 64 = 1.
  • Thus, 658\frac{65}{8} converts to the mixed number 8188\frac{1}{8}.

Therefore, the area of the rectangle is 818\mathbf{8\frac{1}{8}} m².

Answer

818 8\frac{1}{8}