The Vark Questionnaire has been modified to suit children between 12 and 18 years of age, and is a good option for trying to determine your child's best learning style. The questionnaire offers several multiple-choice prompts and questions, and your child has to tick any boxes that apply from the options given. An example of a prompt given on the test is "remember when you learned how to play a new computer or board game. You learned best by:" and the options represent the various different learning styles. This test is quite short, consisting of only one page of questions.
The LD Pride website features a learning styles test designed for people of all ages. The test consists of a series of statements that the child has to rate on a scale of one to four based on how much the statements describe them. The statements are largely simple, such as "I am skillful at designing graphs, charts and other visual displays" and the children have to select a number from one to four to rate the statement. One represents a statement that isn't like them, and four represents a statement that is very much like them. The test consists of 30 of these questions.
Scholastic's learning styles test is tailored to children, but is designed as to be filled in by a parent. The test consists of 10 multiple choice questions, all based on a parent's observation of the child. An example question is "typically, your child chooses to occupy himself at home by:" followed by options for reading, playing computer games, drawing or crafts and playing with action figures. The answers you give to these questions are used to determine the best way for your child to learn.
The Homeschool Views learning styles test consists of 15 multiple choice questions designed to be answered by an adult on behalf of a child. The questions are things such as "how does your child interact with children she's never met before?" followed by three of four options for each question. The only issue with this test is that the options given do not always provide the correct option, and there is no option to select more than one answer, as with Vark's test.