Surds & indices
Click this link to view the KHAN ACADEMY® Numerical aptitude topics:
KHAN ACADEMY® offers great materials that can help build your skills in subjects that are important to you.
You can master basic concepts, explore subjects further or reinforce your knowledge − at your own pace.
Wherever you are in your learning journey, here are links to free materials that may be useful to identify both your strengths and any knowledge gaps in key background subjects.