## Thursday, February 24, 2011

### Chapter 3: Approximation and Estimation - An Introduction (Preparation)

What's the difference between these 2 words - Approximation & Estimation?

On your own, go through the learning activity in the following website
http://www.s-cool.co.uk/gcse/maths/approximations

At the end of the 'visit', you should be able to tell the difference between approximation and estimation, and when each is used in real world...

Write a summary to illustrate the KEY DIFFERENCES between Estimation and Approximation. Submit your write-up as a Comment under this posting.

1. Approximation is rounding off of a number

Estimation is simply guessing a number so long as the answer is reasonable

2. estimation is rounding off the number to 1 significant figure in a number statement so that the it becomes easier to solve.
approximation is rounding off a number to a specific number of figures.

3. Estimation is rounding off the number before doing the sum while Approximation is doing the sum then rounding off the answers

4. The difference between them is that Rounding is the process where you either round up or round down a number which has decimals to a number of significant figures when they are too precise than required,while Estimating is an calculated approximation, taking into account already known figures or previously known facts.Estimations come up with new numbers altogether, while rounding slightly adjusts an already existing number.

5. Approximation is rounding of a certain number while Estimation is guessing the answer of a certain number sentence...

6. Estimation is rounding off both number to 1 significant number before multiplying them together.

Approximation is rounding off a number to a certain number of significant figures required by the question.

7. Rounding off requires you to know the number and to round it off to the nearest and simplest number but estimation is just to calculate a rough number which is more or less close to the actual number

8. estimation is rounding of to make calculation easier while approximation is is rounding of to a specific number of figures

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10. Estimation is rounding off numbers before adding, subtracting, multiplying or dividing to get a rough idea on what the final answer will be.
Approximation is rounding off the number for a easier number to work with.

11. Approximation is rounding of a number to a specific number of digits.
Estimation is to roughly calculate a number close to the original number so that it is easier to use.

12. Approximate means rounding the final answer for example:
29x24=696.
Also this method works on decimals and also whole numbers.

However if you estimate,instead of taking the final answer and rounding it,you take the numbers that are used and approximate them first before getting the final answer.For example:
29x24≈
30x20=600
Also this method only works on one significant figure

13. Estimation is rounding off a number to one significant figure but Rounding off a number is to round it off to a certain number of significant figures.

14. Approximation of a number is rounding off a number to the nearest specified one, whereas estimation is sort of rounding off with a span of a few numbers, an example from the website would be "If you say your garden is 8 metres long you are rounding to the nearest metre and it could be anything from 7.5 to 8.5 metres long.".

15. Approximation is rounding off a certain number to a specific number of figures while Estimation is rounding off a certain number to 1 significant figure in a number statement so that the it becomes easier to solve.

16. Estimation is the process of rounding of the number to the nearest whole number or tens so that the equation is simpler to solve. The answer is estimated and is close the actual answer
Approximation is guessing a number that is close to the answer, but it is a fair answer

17. AN example: "Those two
cows look to be about a hundred yards apart."(estimation) vs "The
surveyor wrote that, to the nearest yard, it is a hundred yards from
between those two markers." (approximation)

18. Estimation is rounding off the number before it is calculated to get the approximate value of the final answer.

Approximation is to round off the number to the nearest number easiest to calculate with.

19. Estimation is the mental skill of making an educated guess and approximation is finding a result precise and close enough to the actual number.

20. Approximation is the rounding up or down of the answer of a sum but estimation is the rounding up or down of the sum before multiplying, dividing, adding or subtracting.

21. Estimation is not so precise as they calculate the approximation in a statement then calculate the answer. Approximation is the rounding off of a answer of a statement.

EG. estimation: 5.4x1.7~5x2=10
approximation: 5.4x1.7=9.18~9

22. Estimation: The rounding off of a number so that the number sentence is easier to solve.

Approximation: The rounding off of the answer of a number sentence.