# Extraction of Cube Roots

Of the various calculating systems given so far, this is probably the most effective and oddly enough, the easiest. The table shown for Cubing Numbers is used and it can be made to reveal the cube root of any number from one to a hundred. For higher numbers, the extraction of cube roots of numbers resulting in more than a hundred, it is only necessary to add noughts to the cubes accordingly.

Ask a member of your audience to work out the cube of any number (say "Two figure number") under one hundred. Suppose their answer came to 804,357. To find the number cubed is very simple:—

Refer to the table for Cubing. The first three figures are 804—greater than 729, the highest possible number. 729 represents the unit 9, so this will be the first figure in the answer. Next take the last number in the total given by the audience—7. Find the cube which ends with seven in the table, it is 27—represented by three—so 3 will be the last figure of the answer. Therefore the cube root of 804,357 is 93. 