[header] How to multiply radicals [title] Make sure that the radicals have the same index. [step] To multiply radicals using the basic method, they have to have the same index. The " index " is the very small number written just to the left of the uppermost line in the radical symbol. 
If there is no index number, the radical is understood to be a square root (index 2) and can be multiplied with other square roots. You can multiply radicals with different indexes, but that is a more advanced method and will be explained later.