Introduction
Approximations are commonly used in day-to-day life. For example, when you plan to meet a friend in the town centre at 4 pm, you might text them to say “I’ll be there in about 20 minutes”. This means that the actual time it takes for you to get there will be less than 20 minutes, but you think it is good enough for your friend to make plans based on this information. This is an approximation. Similarly, a mathematical calculation can be approximated by rounding the values before performing the operations.
A good approximation is always one that is likely to be correct. Simply rounding any number or calculation will lead to incorrect results. The user needs to understand the relative accuracy of a number or calculation and then use appropriate methods.
Rounding Numbers to the nearest 10, 100, 1,000
- To inexact to the closest ten, check out the digit during the tens section.
- To inexact to the closest hundred, check out the digit in the hundreds section.
- Take a gander at the digit in the large numbers segment for the closest thousand.
Let’s do this.
Let’s begin by drawing a vertical line right by the place value digit, which is needed.
Then take a look at the next digit.
- If it’s 5 or more than 5, we will need to add 1 to the previous digit
- If it’s 4 or less than that, we will make no changes to the previous digit
- At last, we will fill any spaces with zeros to the right of the line.
Approximation Examples
The approximation is used for the sake of efficiency. When there are many operations to perform, an approximation can be made instead of repeating those operations for very small changes. If a calculation is too complex for manual calculation, it can be approximated using a computer by rounding the values to a simpler form. Understanding these calculations better enables us to be exposed to mathematical concepts we can use to solve problems. Let us look at some
Approximation examples.
- Cycle 4,853 to the closest 10, 100, and 1,000.
- 485|3 to the closest 10 is 4,850
- 48|53 to the closest 100 is 4,900
- 4|853 to the closest 1,000 is 5,000
- Cycle 76,982 to the closest 10, 100 and 1,000.
- 7698|2 to the closest 10 is 76,980
- 769|82 to the closest 100 is 77,000
- 76|982 to the closest 1,000 is 77,000
It’s worth noting that the solutions for rounding are sometimes the same.
Rounding Off Decimal Places
Rounding to decimals has a variety of applications in real-world situations. One of the most important uses is profit margins, commonly worked out using decimals. It is also applied in scientific fields such as astronomy, where it is critical to make exact calculations. Rounding to decimals can be handled just by using a calculator if you have familiarity with how they work and do not mind spending time doing them manually. Otherwise, you may want to incorporate these functions into spreadsheets or other software you frequently use.
Follow the following steps to round to a decimal place:
- If you’re rounding to one decimal place, look at the first digit following the decimal point; if you’re rounding to two decimal places, look at the second digit.
- A vertical line should be drawn directly to the right of the desired place value digit.
- Take a peek at the digit after that.
- Increase the preceding digit by only if the next digit is 5 or more than 5.
- Keep the preceding digit the same if it’s 4 or less than that.
- Any numbers to the right of the line should be removed.
Examples
Round to one decimal point, then to decimal points: 248.561
- 248.56|61 to 1 decimal place is 248.6
- 248.56|1 to 2 decimal places is 248.56
It’s important to note that your response must have the same degree of decimals as the estimate requested.
Round 0.08513 to 1 decimal place and then to 2 decimal places:
- 0.0|8513 to 1 decimal place is 0.1
Rounding To Significant Figures To Understand The Approximate Meaning
Generally, the method of rounding to a significant figure is used when we are reporting scientific facts. In these situations, the numbers are often huge and need to be rounded off to make them easier to digest and understand. There is no point in ruining the accuracy of your report just so that a number can fit into a space on a spreadsheet or form.
It may be more scientific, but it would also be pointless. The method you use will also change depending on which unit of measurement you are using. It is also important to always use as many significant figures as required by the measurement system (cgs, mks, or sist). For example, it may be possible to report 80 degrees Celsius, but if the measurement system requires 5 significant figures, you should round it down from 80.45 degrees Celsius.
To round to a significant figure:
To round to a significant figure:
- If you’re rounding to one significant figure, look at the very first non-zero digit.
- If you’re rounding to two significant numbers, look at the digit after the first non-zero digit.
- After the necessary place value digit, draw a vertical line.
- Take a peek at the digit after that.
- Increase the preceding digit by one if the following digit is 5 or more.
- Keep the preceding digit the same if it’s 4 or less.
- Fill all spaces to the right of the line with zeros, ending with a decimal point.
Examples
Round 53,879 to 1 significant figure, then 2 significant figures.
- 5|3879 to 1 significant figure is 50,000
- 53|879 to 2 significant figures is 54,000
It is important to note that the number of significant figures in the question corresponds to your response’s maximum number of non-zero digits.
One major number is added after 0.005089, and then 2 significant figures are added.
- 0.005|089 to 1 significant figure is 0.005
- 0.0050|89 to 2 significant figures is 0.0051
- 0.08|513 to 2 decimal places is 0.09
Conclusion
When the right model is difficult to utilise, an approximation can refer to utilising a simplified procedure or model. To make computations easier, an approximation model is used. Approximations may be utilised if accurate representations are not possible due to insufficient information.
The sort of approximation utilised is determined by the information available, the level of precision necessary, the sensitivity of the problem to this data, and the time and effort savings obtained by approximation.