The phrase "a single grade" is correct and usable in written English.
It can be used when referring to one specific level or score in an academic or evaluative context.
Example: "After reviewing the assignments, the teacher decided to assign a single grade for the entire project."
Alternatives: "one grade" or "a lone grade".
In a year, she can pass out 900 packets to a single grade.
Of course if you missed your perfect course by a single grade the future may still be pretty clear.
What happened, as M. R. Werner described in a Reporter at Large piece later that year, was the creation of a single grade, known as Approved Milk.
The uproar, as M. R. Wemer reported in our pages, led to the creation of a single grade of "approved milk".
Another found that raising the average educational attainment in a country by a single grade could significantly reduce the risk of conflict.
While handing your child an app-ladden iPhone can be a hit-or-miss experience, all the Leapster games are configured to a single grade level at once.
The arguments for and against using a single grading system are summarised in Table 3.
As our patients with OA were distributed in different locations, we could not use a single grading system to evaluate all the patients with the current small sample size.
Instead of keeping first grade as a single class they ended up combining first and second grade together.
Six patients permanently discontinued dacomitinib due to treatment‐related AEs, which included grade 4 dyspnea (day 8) and grade 4 pulmonary embolism (day 9) (both in a single patient); grade 3 fatigue (day 14); grade 3 exfoliative rash (day 134); grade 2 allergic dermatitis (day 3); grade 2 fatigue (day 85); and grade 1 fatigue (day 43).
Much of the available data recorded from any individual tumor are lost when the grading technique is used to derive a single quantal grade.
