Fractions on a Number Line: Worded problems

Examples with solutions for Fractions on a Number Line: Worded problems

Exercise #1

A math teacher gives extra points to anyone who completes at least 25 \frac{2}{5} of a piece of work.

Daniel does 12 \frac{1}{2} of the work.

Andy does 16 \frac{1}{6} of the work.

Sara does 27 \frac{2}{7} of the work.

Who does the teacher give extra points to?

Video Solution

Step-by-Step Solution

To solve this problem, we'll compare each student's share of work against 25\frac{2}{5} to determine who receives extra points.

Let's perform these comparisons:

  • Daniel: He completed 12\frac{1}{2} of the work.
    Compare 12\frac{1}{2} with 25\frac{2}{5}:
    Cross-multiply: 1×51 \times 5 vs 2×22 \times 2 -> 5>45 > 4.
    This shows 12>25\frac{1}{2} > \frac{2}{5}.
  • Andy: He completed 16\frac{1}{6} of the work.
    Compare 16\frac{1}{6} with 25\frac{2}{5}:
    Cross-multiply: 1×51 \times 5 vs 6×26 \times 2 -> 5<125 < 12.
    This shows 16<25\frac{1}{6} < \frac{2}{5}.
  • Sara: She completed 27\frac{2}{7} of the work.
    Compare 27\frac{2}{7} with 25\frac{2}{5}:
    Cross-multiply: 2×52 \times 5 vs 7×27 \times 2 -> 10<1410 < 14.
    This shows 27<25\frac{2}{7} < \frac{2}{5}.

Only Daniel completed more than 25\frac{2}{5} of the work. Thus, he receives extra points.

The teacher gives extra points to Daniel.

Answer

Daniel

Exercise #2

Marcus eats 27 \frac{2}{7} of a pizza, while Silvia eats 38 \frac{3}{8} of it.

Who eats less?

Video Solution

Step-by-Step Solution

To solve this problem, we will compare the fractions 27\frac{2}{7} and 38\frac{3}{8} by finding a common denominator and then converting them to equivalent fractions:

  • Step 1: Find the least common denominator (LCD) of 7 and 8. Since 7 and 8 are coprime (they have no common factors other than 1), the LCD is simply their product, 5656.
  • Step 2: Convert each fraction to an equivalent fraction with the denominator of 56.
  • To convert 27\frac{2}{7} to a fraction with a denominator of 56: Multiply both the numerator and the denominator by 8 (since 7×8=567 \times 8 = 56):
    27=2×87×8=1656\frac{2}{7} = \frac{2 \times 8}{7 \times 8} = \frac{16}{56}.
  • To convert 38\frac{3}{8} to a fraction with a denominator of 56: Multiply both the numerator and the denominator by 7 (since 8×7=568 \times 7 = 56):
    38=3×78×7=2156\frac{3}{8} = \frac{3 \times 7}{8 \times 7} = \frac{21}{56}.
  • Step 3: Compare the two fractions 1656\frac{16}{56} and 2156\frac{21}{56}. Since 16 is less than 21, 27\frac{2}{7} is less than 38\frac{3}{8}.

Therefore, Marcus eats less of the pizza than Silvia.

The correct answer is Marcus.

Answer

Marcus

Exercise #3

Andy eats 12 \frac{1}{2} of his lunch, while Daniel eats 14 \frac{1}{4} of his.


Who eats more?

Step-by-Step Solution

To solve this problem, we need to compare the fractions 12 \frac{1}{2} and 14 \frac{1}{4} . Since both fractions have the same numerator, the fraction with the smaller denominator is the larger fraction, indicating which portion is larger.

Step-by-step, here's how it goes:

  • Step 1: Consider the fractions 12 \frac{1}{2} (Andy's portion) and 14 \frac{1}{4} (Daniel's portion).
  • Step 2: Compare these two fractions. Note that 12 \frac{1}{2} has a smaller denominator than 14 \frac{1}{4} . In terms of fractions with the same numerator (1), a smaller denominator means a larger fraction.
  • Step 3: Therefore, 12 \frac{1}{2} is greater than 14 \frac{1}{4} , meaning Andy eats more than Daniel.

Consequently, the solution to the problem is that Andy eats more.

Answer

Andy

Exercise #4

Benjamin ate 47 \frac{4}{7} of a cake and

George ate 69 \frac{6}{9} of the cake.

Who ate the most cake?

Video Solution

Step-by-Step Solution

To solve this problem, we'll compare the fractions representative of the cake portions that Benjamin and George ate.

  • Step 1: Simplify Fractions
    George ate 69 \frac{6}{9} of the cake. Simplifying this fraction, we divide both the numerator and the denominator by their greatest common divisor, which is 3. Thus, 69=23 \frac{6}{9} = \frac{2}{3} .
  • Step 2: Find Common Denominator
    The denominators of the two fractions we are comparing are 7 and 3. The least common multiple (LCM) of 7 and 3 is 21.
  • Step 3: Convert to Common Denominator
    Convert 47 \frac{4}{7} and 23 \frac{2}{3} to fractions with a common denominator of 21:
    - For 47 \frac{4}{7} , multiply the numerator and the denominator by 3: 47=4×37×3=1221 \frac{4}{7} = \frac{4 \times 3}{7 \times 3} = \frac{12}{21} .
    - For 23 \frac{2}{3} , multiply the numerator and the denominator by 7: 23=2×73×7=1421 \frac{2}{3} = \frac{2 \times 7}{3 \times 7} = \frac{14}{21} .
  • Step 4: Compare the Fractions
    Now, compare the numerators: 12 and 14. Since 14 is greater than 12, we can conclude that 1421 \frac{14}{21} (or 23 \frac{2}{3} ) is greater than 1221 \frac{12}{21} (or 47 \frac{4}{7} ).

Therefore, George ate more of the cake.

The correct answer is George.

Answer

George

Exercise #5

The Gardener family puts 34 \frac{3}{4} of their income towards loan repayments, while the Hatfields spend12 \frac{1}{2} of their income on loan repayments.

Which family uses less of their income to on loan repayments?

Video Solution

Answer

The Hatfield family

Exercise #6

Moe ate 27 \frac{2}{7} of a pizza, while

Sarah ate 38 \frac{3}{8} of the pizza.

Who ate the most pizza?

Video Solution

Answer

Sara