Math Foundations: Unit 2 Study Guide

Fractions: Concepts and Operations

1. What a Fraction Represents

A fraction represents a part of a whole. It has two parts:

  • The Numerator (top number) shows how many parts you have.
  • The Denominator (bottom number) shows how many equal parts the whole is divided into.
3 ← Numerator
4 ← Denominator

This means we have 3 parts out of a whole that is divided into 4 equal parts.

Practice Problems:

1. For the fraction $\frac{5}{8}$, the numerator is ____ and the denominator is ____.

2. If a pizza is cut into 12 slices and you eat 5, what fraction of the pizza did you eat?

3. Write the fraction for the shaded part of a circle that is divided into 6 equal parts with 1 part shaded.

4. In a bag of 10 marbles, 3 are red. What fraction of the marbles are red?

2. Equivalent Fractions & Simplifying

Equivalent fractions are different fractions that name the same amount (e.g., $\frac{1}{2}$ is the same as $\frac{2}{4}$).

Simplifying a fraction means to reduce it to its lowest terms by dividing the numerator and denominator by their greatest common divisor (GCD).

Practice Problems: Find the equivalent fraction.

1. $\frac{1}{3} = \frac{?}{9}$

2. $\frac{3}{4} = \frac{?}{12}$

3. $\frac{2}{5} = \frac{4}{?}$

4. $\frac{5}{6} = \frac{?}{18}$

5. $\frac{7}{8} = \frac{14}{?}$

6. $\frac{1}{4} = \frac{?}{20}$

Practice Problems: Simplify the following fractions.

7. $\frac{4}{8}$

8. $\frac{6}{9}$

9. $\frac{10}{15}$

10. $\frac{12}{18}$

11. $\frac{5}{20}$

12. $\frac{14}{21}$

3. Comparing Fraction Sizes

To compare fractions, you can find a common denominator. The fraction with the larger numerator is the larger fraction.

Example: To compare $\frac{2}{3}$ and $\frac{3}{4}$, use a common denominator of 12. $\frac{2}{3} = \frac{8}{12}$ and $\frac{3}{4} = \frac{9}{12}$. Since 9 > 8, then $\frac{3}{4} > \frac{2}{3}$.

Practice Problems: Compare using <, >, or =.

1. $\frac{1}{2}$ ___ $\frac{3}{4}$

2. $\frac{2}{3}$ ___ $\frac{4}{6}$

3. $\frac{3}{5}$ ___ $\frac{1}{2}$

4. $\frac{5}{8}$ ___ $\frac{3}{4}$

5. $\frac{4}{5}$ ___ $\frac{5}{6}$

6. $\frac{7}{10}$ ___ $\frac{2}{3}$

4. Improper Fractions & Mixed Numbers

Improper Fraction: The numerator is larger than or equal to the denominator (e.g., $\frac{5}{3}$).

Mixed Number: A whole number and a fraction combined (e.g., $1\frac{2}{3}$).

Convert Mixed to Improper: (Whole Number × Denominator) + Numerator. Keep the same denominator.

Convert Improper to Mixed: Divide the numerator by the denominator. The quotient is the whole number, the remainder is the new numerator, and the denominator stays the same.

Practice Problems: Convert to a mixed number.

1. $\frac{7}{4}$

2. $\frac{11}{3}$

3. $\frac{9}{2}$

4. $\frac{13}{5}$

5. $\frac{16}{6}$

6. $\frac{25}{8}$

Practice Problems: Convert to an improper fraction.

7. $2\frac{1}{3}$

8. $3\frac{3}{4}$

9. $1\frac{5}{6}$

10. $4\frac{2}{5}$

11. $5\frac{1}{2}$

12. $6\frac{2}{3}$

5. Adding & Subtracting Fractions (Like Denominators)

To add or subtract fractions with the same denominator:

  • Add or subtract the numerators.
  • Keep the denominator the same.
  • Simplify the result if possible.

Practice Problems: Add the fractions.

1. $\frac{1}{5} + \frac{2}{5} = $

2. $\frac{3}{8} + \frac{4}{8} = $

3. $\frac{2}{7} + \frac{3}{7} = $

4. $\frac{5}{12} + \frac{5}{12} = $

5. $\frac{3}{10} + \frac{6}{10} = $

6. $\frac{2}{9} + \frac{4}{9} = $

Practice Problems: Subtract the fractions.

7. $\frac{4}{5} - \frac{1}{5} = $

8. $\frac{7}{8} - \frac{3}{8} = $

9. $\frac{9}{10} - \frac{2}{10} = $

10. $\frac{5}{6} - \frac{4}{6} = $

11. $\frac{11}{12} - \frac{5}{12} = $

12. $\frac{8}{9} - \frac{2}{9} = $