Take Cube Roots of 6-Digit Numbers Mentally

Step 4 Splitting the Cube in 2

Now, suppose we're given an arbitrary number that we know to be a perfect cube. For example, 50653 or 262144. We will tackle the cube root extraction by splitting the number into 2 halves, based on the comma separating the hundreds and thousands positions of the number, and evaluate those 2 numbers separately.

So, if our number is 50653 from above, we would split it at the comma, yielding 2 numbers (50 and 653) which we will evaluate separately, and then put back together to create the final cube root.

Next, we will evaluate the right side of the expression, yielding us the 1's digit of our extracted cube root.