Confused about method to approximate a decimal number.

In summary, to approximate a number to the nearest integer, you only need to consider the tenths place value. If it is less than 0.5, the number should be rounded down to the nearest integer. In the conversation, the number 14.45 is closer to 14 than to 15, so it should be rounded down to 14.
  • #1
arroy_0205
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0

Homework Statement


I need to approximate the number 14.45 to nearest integer.


Homework Equations





The Attempt at a Solution


If I remember correctly, to approximate a decimal up to say 2nd decimal place, I look at the third digit and if this is greater than or equal to 5, then I increase the 2nd decimal place, otherwise keep the 2nd decimal digit as it is. e.g., 13.672 -> 13.67, 13.549-> 13.55
In my case what should I do? Should I first approximate to 1st decimal, then to nearest integer? Then should the answer be 14.45-> 14.5->15 Or is it operationally correct to note that .45<.5 so, 14.45->14? Which approach is correct?
 
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  • #2
arroy_0205 said:
Or is it operationally correct to note that .45<.5 so, 14.45->14? Which approach is correct?

This is the correct approach. If you're rounding to the nearest integer, then you just need to check what the tenths value is. The hundredths and so on won't affect the answer.
 
  • #3
The real point is that .45 is less than 1/2 so 14.45 is close to 14 than to 15.

The moral- don't just follow "rules" thoughtlessly- think about what they mean.
 

Related to Confused about method to approximate a decimal number.

1. How do I approximate a decimal number?

One way to approximate a decimal number is to round it to the nearest whole number. This can be done by looking at the digit to the right of the decimal point. If it is 5 or higher, round the whole number up. If it is 4 or lower, round the whole number down.

2. What is the difference between approximation and estimation?

Approximation is a method of finding a value that is close to the exact value, while estimation is an educated guess based on limited information. Approximation is more precise than estimation.

3. Can I use different methods to approximate a decimal number?

Yes, there are other methods for approximating a decimal number, such as truncating, which involves removing all digits to the right of the decimal point, or using a calculator to find the decimal equivalent of a fraction.

4. Is there a specific number of decimal places I should use when approximating?

The number of decimal places to use when approximating a decimal number depends on the level of accuracy required for the specific situation. In some cases, using just one decimal place may be enough, while in others, more decimal places may be necessary.

5. How can I check if my approximation is accurate?

You can check the accuracy of your approximation by comparing it to the exact value of the decimal number. This can be done by using a calculator or by performing the calculations manually. If the difference between the two values is small, then your approximation is accurate.

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