* The individual student: Some students find certain subjects easier than others. A student who excels in math might find 5th-grade math easier than a student struggling with reading comprehension who might find 5th-grade reading much harder.
* The school and curriculum: Schools and teachers have different teaching styles and expectations. Some 5th-grade classes might be significantly more challenging than others.
* Specific subjects: The difficulty increase isn't uniform across all subjects. A student might find 5th-grade math significantly harder than 4th-grade math but find 5th-grade science easier.
In general, 5th grade introduces more complex concepts and expects a higher level of independent work and critical thinking in most subjects. But the *amount* harder it is is subjective and depends on the factors above.