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Step 2Cubes/Cube Roots
In mathematics, a cube is any number raised to the third power. Said another way, it's any number that is multiplied by itself 2 times. For example 100 cubed = 1003 = 100*100*100 = 1,000,000.
The cube root of a number is exactly the opposite. Think of it as, given a number, the cube root of the number is the number you would have to multiply by itself 3 times to get the current number. So, from the above example:
Cube root of 1000000 = (1000000)(1/3) = 100
By the time you have finished this instructable, you will be able to determine the cube root of any number between 0 and 99 cubed (so, anything from 0 - 970299). And the best part is, you'll be able to do it without the use of a calculator, using nothing more than your mind.
The cube root of a number is exactly the opposite. Think of it as, given a number, the cube root of the number is the number you would have to multiply by itself 3 times to get the current number. So, from the above example:
Cube root of 1000000 = (1000000)(1/3) = 100
By the time you have finished this instructable, you will be able to determine the cube root of any number between 0 and 99 cubed (so, anything from 0 - 970299). And the best part is, you'll be able to do it without the use of a calculator, using nothing more than your mind.
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Jul 27, 2008. 4:58 PMRodolfo
says:
How can I solve 856,700 ???
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Jul 27, 2008. 5:20 PMpurduecer (author)
says:
well...that doesn't sound like a perfect cube, and it quick check reveals it's not. So, splitting it at the comma, 856 is between 729 (93) and 1000(103) so, take the tens digit to be 9. However, not being a perfect cube, my trick incorrectly reveals 0 to be the 1's digit, which it's not. So, to solve for the above number accurately, you'll still want to use a calculator for the time being.
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