|
Obviously if we are approximating numbers that we use in
calculations then there is going to be a difference between the
answer we get by using the approximated values and the answer we
would have got if we had used the exact values. In the IB we
express this difference as the
percentage error. |
Percentage error =
 |
|
Where
 are the approximated value and
 the exact value? |
|
Example:
A
rectangle has sides 3.525 cm by 8.765 cm. |
| a. |
Calculate the exact area of the rectangle |
| |
Answer:
Area = 3.525 x 8.765
cm² = 30.896625 cm² |
| b. |
Calculate the area of the rectangle after rounding the dimensions
to one decimal place. |
| |
Answer:
Area = 3.5 x 8.8 cm² = 26.4cm² |
| c. |
Calculate the percentage error of the area in rounding the
dimensions to one decimal place. Give your percentage error to
one decimal place. |
| |
Answer:
Percentage error =
= -14.4% |
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