The phrase "a number of optional" is correct and usable in written English.
It can be used when referring to several choices or alternatives that are not mandatory.
Example: "In the course syllabus, there are a number of optional readings that students can choose to explore."
Alternatives: "several optional" or "a variety of optional".
In addition to the required study procedures, the Patient Consent Form also includes a number of optional elements to which parents may separately consent or decline, including the option to include or exclude the child's recessive carrier mutations in the germline WES report.
However, there are a number of optional parameters that might be invoked to optimize a particular observation.
Apart from these obligatory documents, there are a number of optional agreements concerning services, such as parcel post and cash on delivery.
Students may pick one of a number of optional, formal concentration templates or design their own M.S. program in consultation with an adviser.
In the empirical part of our study, we have submitted a number of optional classifications to active mechanical engineering designers to see what classification they would prefer as the basis for an automated knowledge-based system on the Internet.
Each team is also allowed a number of optional time-outs, and time is automatically stopped for a variety of reasons during play and for commercials during televised contests, with the result that games last well beyond the actual playing time.
Midnight 10) BLUE VAN SPECIAL In Krakow, the most popular street food is the zapiekanka, a toasted open-faced baguette topped with mushrooms and cheese (or any number of optional add-ons).
MEME has a large number of optional inputs to fine-tune its performance.
In SAM, each alignment line has 11 mandatory fields and a variable number of optional fields.
While the Mazda3 has a number of standard or optional features that are rarely found in this class of cars in the U.S., features such as power seats, traction control or an emergency communications system like GM's OnStar service are not available.
A number of properties are optional: these, properties that will be defined in the future, and custom properties that are not a part of the formal specification, are stored in a way that preserves the read/modify/write integrity for algorithms that do not care to implement them.
