Examples with solutions for Comparing Fractions: The common denominator is smaller than the product of the denominators

Exercise #1

Fill in the missing sign:

1456 \frac{1}{4}☐\frac{5}{6}

Video Solution

Step-by-Step Solution

To solve this problem, we'll compare the fractions: 14 \frac{1}{4} and 56 \frac{5}{6} .

  • Step 1: Determine the least common denominator (LCD) of the fractions' denominators, 4 and 6. The LCM of 4 and 6 is 12.
  • Step 2: Convert 14 \frac{1}{4} to an equivalent fraction with a denominator of 12:

14=1×34×3=312 \frac{1}{4} = \frac{1 \times 3}{4 \times 3} = \frac{3}{12}

  • Step 3: Convert 56 \frac{5}{6} to an equivalent fraction with a denominator of 12:

56=5×26×2=1012 \frac{5}{6} = \frac{5 \times 2}{6 \times 2} = \frac{10}{12}

  • Step 4: Compare the numerators: 312 \frac{3}{12} compared to 1012 \frac{10}{12} .

Since 3 3 is less than 10 10 , we conclude that 14 \frac{1}{4} is less than 56 \frac{5}{6} .

Thus, the missing sign is < .

Answer

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Exercise #2

Fill in the missing sign:

3814 \frac{3}{8}☐\frac{1}{4}

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the denominators of the fractions 38\frac{3}{8} and 14\frac{1}{4}.
  • Step 2: Determine the least common denominator of 8 and 4.
  • Step 3: Convert each fraction to have this common denominator.
  • Step 4: Compare the fractions by examining their numerators.

Let's begin by determining the least common denominator (LCD) of the fractions:

The denominators are 8 and 4. The least common multiple (LCM) of these two numbers is 8.

Convert each fraction to an equivalent fraction with the common denominator of 8:

  • 38\frac{3}{8} already has the denominator 8, so it remains 38\frac{3}{8}.
  • For 14\frac{1}{4}, convert by multiplying the numerator and denominator by 2:
  • 14=1×24×2=28\frac{1}{4} = \frac{1 \times 2}{4 \times 2} = \frac{2}{8}.

Now, compare these equivalent fractions: 38\frac{3}{8} and 28\frac{2}{8}.

Since 3>23 > 2, it follows that 38>28\frac{3}{8} > \frac{2}{8}.

Therefore, the correct sign for the missing space is >>.

Thus, 38>14\frac{3}{8} > \frac{1}{4}.

Answer

>

Exercise #3

Fill in the missing sign:

25615 \frac{2}{5}☐\frac{6}{15}

Video Solution

Step-by-Step Solution

To solve this problem, we'll take the following steps:

  • Step 1: Simplify the fraction 25\frac{2}{5}.
  • Step 2: Simplify the fraction 615\frac{6}{15}.
  • Step 3: Compare the simplified forms.

Let's go through these steps:

Step 1: 25\frac{2}{5} is already in its simplest form because 2 and 5 have no common divisors other than 1.

Step 2: Simplify the fraction 615\frac{6}{15}:
- The greatest common divisor (GCD) of 6 and 15 is 3.
- Divide both the numerator and the denominator by their GCD to simplify:
615=6÷315÷3=25 \frac{6}{15} = \frac{6 \div 3}{15 \div 3} = \frac{2}{5}

Step 3: Compare the simplified forms:
Both 25\frac{2}{5} and 615\frac{6}{15} simplify to 25\frac{2}{5}. Thus, they are equivalent.

Therefore, the correct mathematical sign between the fractions 25\frac{2}{5} and 615\frac{6}{15} is = = .

So, the missing sign is =\mathbf{=}.

Answer

= =

Exercise #4

Fill in the missing sign:

4634 \frac{4}{6}☐\frac{3}{4}

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given fractions 46 \frac{4}{6} and 34 \frac{3}{4} .
  • Step 2: Calculate the least common denominator (LCD) of 6 and 4.
  • Step 3: Convert each fraction to have the common denominator and compare numerators.

Now, let's work through these steps:

Step 1: The given fractions are 46 \frac{4}{6} and 34 \frac{3}{4} .

Step 2: Find the least common denominator of 6 and 4. The prime factorization of 6 is 2×3 2 \times 3 and of 4 is 22 2^2 . The LCD is 22×3=12 2^2 \times 3 = 12 .

Step 3: Convert each fraction to this common denominator.

  • Convert 46 \frac{4}{6} to have a denominator of 12: Multiply both numerator and denominator by 2 to get 4×26×2=812 \frac{4 \times 2}{6 \times 2} = \frac{8}{12} .
  • Convert 34 \frac{3}{4} to have a denominator of 12: Multiply both numerator and denominator by 3 to get 3×34×3=912 \frac{3 \times 3}{4 \times 3} = \frac{9}{12} .

Compare the numerators: 8 and 9. Since 8 is less than 9, we find that 46<34 \frac{4}{6} < \frac{3}{4} .

Therefore, the correct sign to fill in is < < , and the correct answer is:

46<34 \frac{4}{6} < \frac{3}{4} .

Answer

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Exercise #5

Fill in the missing sign:

14512 \frac{1}{4}☐\frac{5}{12}

Video Solution

Step-by-Step Solution

To solve this problem, we'll use the cross-multiplication method to compare the fractions 14 \frac{1}{4} and 512 \frac{5}{12} .

  • Step 1: Cross-multiply the fractions.
    We multiply the numerator of the first fraction by the denominator of the second, and the numerator of the second fraction by the denominator of the first:
  • 1×12=12 1 \times 12 = 12
  • 5×4=20 5 \times 4 = 20
  • Step 2: Compare the results from cross-multiplication.
    Now, compare the results: 12 12 and 20 20 .
    Since 12<20 12 < 20 , it follows that 14<512 \frac{1}{4} < \frac{5}{12} .

Therefore, the correct sign to fill in the blank is < < .

The solution to the problem is 14<512\frac{1}{4} < \frac{5}{12}.

Answer

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Exercise #6

Fill in the missing sign:

51278 \frac{5}{12}☐\frac{7}{8}

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the least common multiple (LCM) of the denominators 12 and 8.
  • Step 2: Convert each fraction to have this common denominator.
  • Step 3: Compare the converted fractions by examining their numerators.

Let's proceed with the solution:
Step 1: The LCM of 12 and 8 needs to be found. The factorization of 12 is 22×3 2^2 \times 3 and for 8 is 23 2^3 . The LCM is 23×3=24 2^3 \times 3 = 24 . Therefore, the common denominator is 24.

Step 2: Convert each fraction to the new denominator:

  • Convert 512 \frac{5}{12} : The equivalent fraction is found by multiplying both the numerator and the denominator by a number that equals the common denominator when the original denominator is multiplied by it. 24÷12=2 24 ÷ 12 = 2 . Thus, multiply both the numerator and denominator by 2: 5×212×2=1024 \frac{5 \times 2}{12 \times 2} = \frac{10}{24} .
  • Convert 78 \frac{7}{8} : Similarly, multiply by 24÷8=3 24 ÷ 8 = 3 : 7×38×3=2124 \frac{7 \times 3}{8 \times 3} = \frac{21}{24} .

Step 3: Compare the two equivalent fractions 1024 \frac{10}{24} and 2124 \frac{21}{24} . Comparing the numerators while the denominators are the same: 10 < 21.

Therefore, 512 \frac{5}{12} is less than 78 \frac{7}{8} .

Thus, the correct sign to fill in is < < .

Answer

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Exercise #7

Fill in the missing sign:

14516 \frac{1}{4}☐\frac{5}{16}

Video Solution

Step-by-Step Solution

To solve this problem, we'll compare the two fractions, 14 \frac{1}{4} and 516 \frac{5}{16} , by converting them to have a common denominator:

  • Step 1: Identify the denominators of the two fractions: 4 and 16.
  • Step 2: Find the least common denominator (LCD). The smallest number both 4 and 16 can divide into is 16.
  • Step 3: Convert 14 \frac{1}{4} to have a denominator of 16: Multiply both the numerator and the denominator of 14 \frac{1}{4} by 4 to obtain 416 \frac{4}{16} .
  • Step 4: Now we compare the two fractions: 416 \frac{4}{16} and 516 \frac{5}{16} .
  • Step 5: Since both fractions have the same denominator, compare the numerators: 4 and 5.

Based on the comparison, 4 is less than 5, which means 416 \frac{4}{16} is less than 516 \frac{5}{16} .

Therefore, the correct sign to fill in the blank is < < .

Answer

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Exercise #8

Fill in the missing sign:

17414 \frac{1}{7}☐\frac{4}{14}

Video Solution

Step-by-Step Solution

To solve this problem, let's proceed as follows:

Step 1: Simplify the fractions.
The first fraction is 17 \frac{1}{7} , which is already in its simplest form.
The second fraction is 414 \frac{4}{14} , which can be simplified by dividing both the numerator and denominator by their greatest common divisor, 2:
4÷214÷2=27 \frac{4 \div 2}{14 \div 2} = \frac{2}{7} .

Step 2: Compare the simplified fractions.
Now, compare 17 \frac{1}{7} and 27 \frac{2}{7} .
Since both fractions have the same denominator (7), we compare the numerators directly:
Since 1<2 1 < 2 , it follows that 17<27 \frac{1}{7} < \frac{2}{7} .

Therefore, the missing sign in 17414 \frac{1}{7} ☐ \frac{4}{14} is <\lt.

The correct answer to this problem is < \lt .

Answer

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