Comparing Fractions
Aligned to 4.NF.A.2 — Common Core State Standards for Mathematics.
What this lesson teaches
To compare fractions with different denominators, give them the same denominator by finding a common one, then compare the numerators. You can also compare each fraction to a benchmark like 1/2.
Worked examples
Example 1
Compare 3/5 and 5/8. A common denominator is 40. 3/5 = 24/40 (times 8 top and bottom). 5/8 = 25/40 (times 5 top and bottom). Now compare numerators: 24 < 25, so 3/5 < 5/8.
Example 2
Compare 2/3 and 3/4. A common denominator is 12: 2/3 = 8/12 and 3/4 = 9/12. Since 8 < 9, 2/3 < 3/4.
Example 3
Sometimes you do not need a common denominator. 5/8 is more than half and 3/8 is less, so 5/8 > 3/8 without any conversion.
Practice questions
- Compare 2/3 and 3/4 using a common denominator.
- Compare 4/10 and 1/2 using a benchmark.
- Put these in order from least to greatest: 1/2, 2/5, 3/4.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Comparar fracciones
Para comparar fracciones con denominadores diferentes, dales el mismo denominador buscando uno común y luego compara los numeradores. También puedes comparar cada fracción con un punto de referencia como 1/2.
Ejemplo 1: Compara 3/5 y 5/8. Un denominador común es 40. 3/5 = 24/40 (por 8 arriba y abajo). 5/8 = 25/40 (por 5 arriba y abajo). Ahora compara los numeradores: 24 < 25, entonces 3/5 < 5/8.
Ejemplo 2: Compara 2/3 y 3/4. Un denominador común es 12: 2/3 = 8/12 y 3/4 = 9/12. Como 8 < 9, entonces 2/3 < 3/4.
Ejemplo 3: A veces no necesitas denominador común. 5/8 es más de la mitad y 3/8 es menos, así que 5/8 > 3/8 sin convertir nada.
More Number & Operations—Fractions lessons
Teach this lesson today
An AI tutor that guides with questions instead of just giving answers — all K–12 core subjects, every child in the family.
Start free — no card required