February 16, 2012 | 
Author Here’s an example of a SPEED MATH shortcut for CUBING 3-DIGIT NUMBERS NEAR A BASE: (Cub) NrB3 from the CUBING AND CUBE ROOTS category.
When can I use this method?
For cubing any 3-digit numbers.
The number can be either < or > a Base number.
Download Practice sheet for CUBING 3-DIGIT NUMBERS NEAR A BASE
Notes –
- When selecting a Base number, prefer a number that is near the number to be squared as well as it should be easy to multiply with (prefer round numbers).
- This method uses the concept (B + a)3 = [(B + 3a) B2] + [(3a2) B] + [a3], where ‘(B + a)’ is the number to be squared, ‘B’ is the Base number and ‘a’ is the difference.
- Whenever the number is more than the Base number, the difference is written as positive (+ve).
- Whenever the number is less than Base Number, the difference is written as negative (-ve).
Related Shortcuts –
Cubing Numbers near 10: (Cub) Nr10
Cubing Numbers near 100: (Cub) Nr100
Cubing Numbers near 1000: (Cub) Nr1000
Cubing 2-digit Numbers near a Base: (Cub) NrB2
Cubing 4-digit Numbers near a Base: (Cub) NrB4
We hope this helps you in getting to the answer faster. You can apply this shortcut in the exams and get to the answer before anyone else can.
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Posted in (Cub) NrB3, Cubing and Cube Roots, Speed Math | 
Tags: Cubing and Cube Roots, Math Tricks, Mental Math, Speed Math
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