Rounding and approximations (OCR GCSE Maths): Flashcards
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Definition of rounding
Definition of rounding
Process of simplifying a number while keeping its value close to the original
The key digit in rounding
The key digit in rounding
Last digit you want to keep in your rounded number
Rule when unwanted digit is or above
Rule when unwanted digit is or above
Add one to the key digit
Rule when unwanted digit is less than
Rule when unwanted digit is less than
Leave the key digit as it is
Key digit with unwanted digit or above
Key digit with unwanted digit or above
Changes to and increases digit to left by one
Decimal places (dp)
Decimal places (dp)
How many digits kept after the decimal point
Number of decimal places to give in answer
Number of decimal places to give in answer
Exactly the number requested, no more, no less
First significant figure
First significant figure
The first non-zero digit in a number
What does the symbol mean?
What does the symbol mean?
Approximately equal to
When are approximations useful?
When are approximations useful?
When exact answer not needed or working without calculator
Second significant figure
Second significant figure
Digit immediately to right of first significant figure
Why use zeros when rounding to 10, 100, 1000?
Why use zeros when rounding to 10, 100, 1000?
To maintain the correct place value
Size of rounded number using sig figs
Size of rounded number using sig figs
Should be similar to the original number