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Stuck in the app, found a bug or have a question about a practice test? Get in touch and we will get back to you.

Contact us

Tell us what happened and, if you can, which device and version of Dos you use. It helps us sort things out faster.

Report an incorrect question

Does a calculation look wrong, or does an answer seem incorrect? Tell us which topic it was in and roughly how the question was worded, and we will put it right.

Frequently asked questions

Answers to what we are asked most often, including how the marking works and how your plan is built.

Suggestions for improvements

Missing a topic, a feature or a way to practise? We read everything that comes in.