Study Guide Generator — illustrative example

INPUT
Create a compact study guide for equivalent fractions and adding fractions with common denominators. Include one worked example, one mistake and one practice answer.

RESULT
Key idea: equivalent fractions represent the same value; multiplying numerator and denominator by the same nonzero number preserves that value.
Example: 1/2 = 2/4.
Addition rule: with a common denominator, add numerators and keep the denominator.
Worked example: 1/7 + 3/7 = 4/7.
Common mistake: adding denominators would give 4/14, which is not the sum.
Practice: 2/5 + 1/5 = ?
Answer: 3/5.

REVIEW
A study guide should organize relationships and key questions, not merely shorten every paragraph. Include examples that help the learner check understanding.

This is a teaching example, not a live execution record.