See also the
Dr. Math FAQ:
3D and higher
Browse Middle School Fractions & Percentages
Stars indicate particularly interesting answers or
good places to begin browsing.
Selected answers to common questions:
Finding a least common denominator (LCD).
Comparing/ordering fractions; equivalent fractions.
Improper fractions and mixed numbers.
Converting fractions to/from decimals.
Fractions and repeating decimals.
Finding a percentage.
- 100 Percent of Daily Allowance of Iron [09/30/2001]
A common foodstuff is found to contain .00125% iron. The serving size is
87.0 grams. If the recommended daily allowance is 18mg of iron, how many
servings would a person have to eat to get 100% of the daily allowance of
- 2a/5 or 2a Divided by 5? [12/13/2001]
Why, when writing a division problem, do you write 2a over 5 instead of
2a divided by 5?
- 33 1/3 Percent as a Fraction [08/03/2003]
I need help turning percents like 33 1/3%, 2.5%, and other percents
like that into fractions.
- (9/2)/(3/4): A Picture [03/27/2003]
We were trying to find a division fraction question and everything we
came up with turned into a multiplication fraction problem. Why is
- Adding and Subtracting Fractions [10/25/1999]
Can you help me learn to add and subtract fractions?
- Adding Mixed Numbers [04/13/1999]
How do you add mixed numbers without renaming?
- Algebraic Fractions [5/27/1996]
How would you solve for x and find the least common denominator in the
equation 2/x = 4/3?
- Algebra using Fractions [5/27/1996]
Please show me how to solve this equation: (5/8)X = 9
- Cancelling Fractions [03/06/2002]
How do I cancel this problem: 1/5 x 40/1 x 1/2 ?
- Changing Decimals to Fractions and Reducing [12/12/2002]
Could you please help me to understand, in the simplest way, how to
write a decimal as a lowest-term fraction or mixed number?
- Checking Proportions using Square Roots [04/11/2002]
Multiply two fractions, and then take their square root. If it equals
one of the fractions you began with, you have a true proportion. Does
this always work?
- Clarifying Fraction Notation [07/02/1997]
.83 1/3... a trick problem?
- Congruent Fractions [04/03/1997]
What are congruent fractions?
- Converting Fractions to Decimals [01/08/1997]
How do you convert fractions to decimals? How do you turn decimals into
- Converting Ratios to Percentages [08/03/2003]
How do I convert 1:200 to a percentage?
- Converting Repeating Decimals to Fractions [11/19/1997]
I know .333333333333 is 1/3, but what is the trick to it?
- Cross-Multiplication [08/04/2002]
Can you explain cross-multiplication?
- Diagram Showing Division of Fractions [01/13/2002]
I understand how to divide fractions, but would like to be able to draw
this problem in a diagram: (2/3)/(3/4) = 8/9.
- Dividing a Fraction by a Fraction [08/11/1997]
Can you help students visualize a problem such as: 1/3 / 1/2 = 2/3 ?
- Dividing by a Negative Fraction [01/24/2002]
I understand how to divide fractions, but what if one of them is
- Dividing Fractions [7/5/1996]
I always get stuck on dividing fractions.
- Dividing Fractions to find Decimals [03/12/2001]
Why does dividing the numerator by the denominator give you the decimal
form of a fraction?
- Division [11/25/1997]
How do you divide 1,000,000,000,000 by 999,999,999,999,999,999,999?
- Employee Pay Schedule [07/12/2003]
For a particular job, Moe should get 40% of the gross pay, Larry
should get 30%, and Curly should get 30%, assuming they all work the
same number of hours. But how should the money be divided if they
work different numbers of hours?
- Explaining Division of Fractions [08/11/1999]
Can you give a practical explanation of why the 'invert-and-multiply'
rule for division of fractions works?
- Explaining Fractions [11/06/2001]
I am a practicum student in a 8th grade math class. The teacher and I
don't know how to explain to the students why you can do this manuever.
c=d/g; c/d=g; d/c=g.
- Figuring a Percentage [5/24/1996]
What percentage is 3 times as many?
- Figuring a Tax [05/13/2003]
I work in insurance. We have a premium of $75,329. This premium
needs to be increased by a tax of 3.75%...
- Figuring Percentage of Increase [09/05/2001]
In 1990, Allen County, Kansas, had 14,385 people. Now, in 2001, it
contains 14,905 people. How do I calculate the increase, using a
- Finding a Percentage [01/26/2001]
How do you arrive at a percentage that a number is of a number? Example:
what percent of 32000 is 2000?
- Finding Percentage of Increase [06/07/2003]
Find the percentage increase: old, $50.50; new $75.75.
- Finding Percentages [12/5/1996]
I want to know how to find percents of a number - for example, how to
find 13 percent of 29.
- Finding the Lowest Common Denominator [12/11/1995]
What is the most efficient way to find the lcd (lowest common
- Fractional Exponents [08/09/1997]
Is there a proof for X^1/2 = the square root of X?
- Fraction Bar Name [12/14/1996]
What is the name of the little line that separates the divisor from the
dividend in a standard division question?
- Fraction Basics [7/21/1996]
I don't understand how to do fractions.
- Fraction Diagrams [03/13/2002]
In an adult condominium complex, 2/3 of the men are married to 3/5 of the
women. What fraction of the residents are married?
- A Fraction Divided By a Fraction [8/30/1995]
What is 18/6 divided by 2/3?
- Fraction Multiplication [7/22/1996]
The meaning of the dot between two fractions.
- Fraction Multiplication and Division [02/10/2001]
How do you do calculations like 2 1/10 * 7 5/8 or 27/30 over 75/100?