Breaking The Problem Up Into Multiple Parts
Given the problem
we can break it up into something we can calculate quickly such as:
2300 + 100 = 2400
40 + 20 = 60
In the first part, we just removed the 45 and 23 so that we could easily add 100 to 2300. In the second part we changed the 45 and 23 to 40 and 20, since it is part of a larger number, and the 5 and 3 won’t make a big difference in the final number. 40 + 20 is the same as 4 + 2 with an added zero, giving us 60. Then we sum both:
2400 + 60 = 2460
The exact answer is 2468, which is very close to our estimate.
What Is Estimating In Maths
Estimating in maths is a way of approximately calculating an answer to check its accuracy . You shouldnt need to use a calculator or any written methods when estimating, even with large numbers or decimal numbers.
Estimating numbers will always require you to use skills from rounding numbers in one way or another.
Rounding To The Nearest 0
Given the problem
we can break the problem up in a number of different ways, such as:
22 × 10 = 220
20 × 12 = 240
Both of these rely on changing the values such that they end in 0s, making it easier for us to estimate the answer. Multiplying by 10 is one of the easiest multiplication problems we learn, since it involves just adding a 0 to whatever is being multiplied by 10.
The exact value is 264, and our second, more accurate estimation, was 240. Depending on how accurate we need to be, 240, or even 220 may be a good enough estimation of 264.
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Estimation Is A Skill For Life
As you walk around and live your life, imagine if you could easily estimate:
- how much a bill will be,
- which item is the best value for money
- the size, areas and angles of things
Also, it would be great if you could quickly guess how many people are in a room, how many cars in the street, how many boxes on the shelf, or even how many seagulls on the beach.
We are not talking exact answers here, but answers that are good enough for your life.
Making Math Problems Easier By Estimating Values
Estimation is a quick way to work out the approximate answer to a math problem. Estimation is a great way to check your work. To estimate, you need to know how to round numbers. Once you learn to round numbers and estimate, you can do more complex math problems in your head.
Estimating is an important part of math and very handy for everyday life for making sure you are paying the right amount of money when you go shopping , or for working out lengths of time, distance, weight, etc.
For example, say you are adding 527 + 327 + 91 + 83 + 411
This is a pretty complex sum and one that will take time to solve. If you need to work out the rough answer quickly, or if you want to cross-check that your final calculations were correct, you can make this addition easier by rounding each number to the nearest hundred and then adding them:
500 + 300 + 100 + 100 + 400 = 1,400
The approximate answer is 1,400
which isnt far off the exact answer: 1,439.
The same goes for multiplication. Say you want to multiply
511 x 403
You again round the numbers to the nearest 100:
500 x 400 = 200,000
Not far off the exact answer: 205,933.
But watch out! You have to consider how you are rounding the numbers. Your estimations can quite wrong. Youll arrive at bad estimates when you:
- Round numbers that are close to the middle of the range, such as 349 or 562.
- Round too many numbers in the same direction
- Multiply or divide rounded numbers
Lets say you are multiplying 242 X 437
You round both numbers:
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Learn How To Estimate A Sum With Examples
- Category:
In this post, we will learn to estimate a sum.
Do you know what estimating a sum can help us with? When we have to do an operation mentally, often we do not need the exact result but an estimate of the outcome.Other times, after we have done an operation on paper and want to verify that the amount we got is reasonable, an estimate of the sum also helps us.It is quite useful, right? Today we will show you some very simple steps to learn how to estimate a sum.
A Special Case: Estimating For Work
You will almost certainly come across estimates for work to be done, whether from a builder, plumber, mechanic or other tradesperson.
In this case, the tradesperson concerned has probably estimated how much time they are likely to take to do the work, multiplied it by their hourly or daily rate, and perhaps added additional charges for materials or a call-out.
They may also have added a contingency for extra work needed, which is likely to be 10 or 20%, and will mean that you are not unpleasantly surprised by the bill if they find something unexpected that needs fixing.
An estimate is not legally binding. It is just what it says: an estimate.
However, a quote or quotation for work done is legally binding on cost, provided that the work done is what was quoted for. However, if you have asked for extra work: just add that bit or do that while youre here, dont be surprised if the bill is larger than you were expecting.
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What Is The Learning
- Reasoning and Analyzing – use reasoning to determine the estimate.
- Understanding and Solving – engaging in estimating using multiple strategies
- Communicating and Representing – explain and justify estimates and represent understanding on recording template using words and/or pictures
- Connecting and Reflecting – connecting different mathematical ideas and reflect on reasoning
The General Rule Of Estimation
In all cases of rounding, we need to do the following:
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Examples Of Estimating Calculations
A pencil costs 98p and you want to buy 29 one for each child in the class. You would estimate that this would cost £29.
A bottle of fizzy drink holds 2 litres and you want to share it amongst 8 friends. You could estimate, by eye, that each friend could get half a glass each
KS2 SATs Questions: Place Value
25 Arithmetic and Reasoning maths questions on place value, targeting knowledge of base ten number system and ability to manipulate numbers, especially larger and decimal numbers.
Estimation Approximation And Rounding
Sometimes, you may find it helpful to know the approximate answer to a calculation.
You may be in a shop and want to know broadly what youre going to have to pay.
You may need to know roughly how much money you need to meet a couple of bills.
You may also want to know roughly what the right answer to a more complicated calculation is likely to be, to check that your detailed work is correct.
Whatever your precise need, you want to know how to estimate or approximate the right answer.
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Learn To Estimate In Lengths Of Time
Estimation activities involving time have a lot of real-life application. How long does it take to do something? Is it measured in seconds, minutes, days? Visit the link below for free printable worksheets about estimating time.
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12. Try more time estimation activities.
Once you know how long it takes to do something, you can estimate how many times you can do it in a given timeframe. Give kids practice with a free printable thats perfect for the 100th day of school.
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13. Apply estimation activities to math problems.
Even when kids get the hang of estimating in real life, they may struggle to understand the purpose of the concept when applied to math problems on paper. This page from one teachers math journal makes the benefits of estimation clear: not only is it faster, but it helps us determine if our exact answer is reasonable.
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Estimated Time Of Arrival
Estimated time of arrival is used frequently used when travelling. Trains, buses, planes, ships and in-car satellite navigation all use ETA.
The ETA is based on distance and speed of travel, it is estimated because it cannot take into account changes to speed during the journey. Your flight may arrive early because of favourable tail winds. Your road trip may take longer than expected because of traffic.
The ETA is usually calculated by a computer and can change during your trip. As you near your destination, more data becomes available so the estimated time that you will arrive becomes more accurate.
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Build Number Sense With Estimation Activities
Try using a series of estimation jars, with the correct amounts marked on several and one of the series left a mystery for kids to estimate. They use the numbers they know to determine where the mystery jar fits into the sequence and how many items it might reasonably contain.
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How To Calculate Speed
First off, lets talk about what speed is in the first place. Speed is just a measure of how fast something or someone is moving. We usually measure it in miles-per-hour or kilometers-per-hour, and those units pretty much tell you everything you need to know about speed. Namely, if you are traveling at a given speedsay 55 miles-per-hourand you travel for 1 hour, then after that hour you will have traveled 55 miles: 55 miles-per-hour x 1 hour = 55 miles.
So how is speed actually calculated? Its pretty easy. In fact, the units you measure speed inmiles-per-houralmost give away the answer. All you have to do is divide the total distance traveled by the total amount of time it takes to do the traveling , and the number you get out will tell you the average speed traveled over the course of that 1 hour.
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How To Estimate How Fast Someone Is Running
Learn how math can help you estimate how fast your favorite football player is running and convert this speed into units youre familiar with.
A few weeks ago I had a conversation with the former host of QDTs Modern Manners Guy, Trent Armstrong, in which Trent said something along the lines of: I’ve always wondered how to tell how fast a football player is going based upon how quickly they run from, say, the 50 to the 40 yard line. And I thought: Thats a great question!especially since the American football season is just getting started. So, thats exactly what were going to talk about today: How can you gauge how fast a football player is running by watching them pass the lines?
Estimating To Different Place Values
Let’s assume that you want to estimate the total cost of several different items in your grocery list or that there are a few gift items you want to buy.
How would you roughly calculate the amount of money you’d need?
You would round the prices to the nearest tens place because it involves money and it becomes easier to calculate when you round off in this way.
If you are working with extremely large numbers, you might want to round the number to the nearest one million or one billion.
Did we use the same rounding off techniques in all these situations?
There are no hard and fast rules when you want to estimate the outcomes of numbers.
The procedure varies with the degree of accuracy required as well as how quickly we need the estimate.
Example: We need to estimate \
to the nearest whole number.
to the nearest thousand.
to the nearest tenth.
To estimate \ to the nearest whole number, we need to check the number in the tenth place.
The digit in the tenths place is 6, so we need to round up.
Hence, we increase the digit in the units place by 1
Then we get the number 854917 + 1 = 854918
\ The estimation of \ is \
To estimate \ to the nearest thousand, we need to check the number in the hundreds place.
4 is in the thousands place. The digit to its right is 9
So, we round up 4 i.e., increase the digit in the thousands place by 1
Then we get the number 854000 + 1000 = 855000
\ to the nearest tenth: we need to check the number in the hundredths place.
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If A Perfect Answer Isn’t Feasible To Obtain
Suppose you’ve been approached by someone who wants you to mow the lawns at a golf course. They ask you how much you’re going to charge to do the job. Since you’ve never done it before, you don’t know how long it’s going to take you. So you’re going to have to make an estimate. You think to yourself, “Well, it takes me x hours to mow my lawn, and theirs is about 10 times as big as mine,” and you use that information to come up with a price. You’ve just estimated. Until you’ve actually done the job, there’s no way to know how long it’s going to take to do it, so you had to make your best guess.
Self-employed people who do contract work do this kind of estimating all the time.
Sometimes answers aren’t feasible to obtain because you don’t have a calculator available, and you’re dealing with nasty numbers. Suppose for some strange reason you had to multiply 18.9563 times 25.1158, but you didn’t have either a calculator or pen and paper available. If you don’t need a perfect answer, you can say, “Well, 18.9563 is pretty close to 20, and 25.1158 is pretty close to 25. Twenty times twenty-five is 500, and that’s close enough.” .
Estimating In Real Life
We use estimating every day in real life probably without even noticing. If you are buying a packet of crisps for 99p and a drink for £1.99, you would estimate the total cost to be around £3 .
You might be considering refilling your car with petrol, but if you know how many miles per gallon your car does, and how much petrol you have left, you might be able to estimate how far you can go before refilling.
Estimating is also often used in professional contexts such as in project planning and product development.
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Video Lesson On Numbers
To learn more Maths-related concepts, stay tuned with BYJUS The Learning App and explore more videos.
Put your understanding of this concept to test by answering a few MCQs. Click Start Quiz to begin!
Select the correct answer and click on the Finish buttonCheck your score and answers at the end of the quiz
Teach Them The Ish Concept
Even preschoolers can begin to understand estimation. Read the book Ish by Peter H. Reynolds, in which a boy learns to enjoy the process of drawing rather than always worrying about the end result. When he thinks his drawing of a vase doesnt look right, his little sister says it looks vase-ish, or close enough to the real thing. Translate that concept to estimation activities like guessing the number of objects in jars.
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Examples Of Estimate In A Sentence
estimatedestimateestimatedestimatesestimatesestimateestimatesestimateestimateestimate Chicago Tribuneestimate BostonGlobe.comestimate Forbesestimate New York Timesestimate Baltimore Sunestimate The Indianapolis Starestimate USA TODAYestimate The Arizona RepublicForbesestimate Quartzestimate USA TODAYestimate Washington PostestimateCBS NewsestimateWSJestimate Fortuneestimate Anchorage Daily News
These example sentences are selected automatically from various online news sources to reflect current usage of the word ‘estimate.’ Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
How Estimation Is Done
Estimation is often done by sampling, which is counting a small number of examples something, and projecting that number onto a larger population. An example of estimation would be determining how many candies of a given size are in a glass jar. Because the distribution of candies inside the jar may vary, the observer can count the number of candies visible through the glass, consider the size of the jar, and presume that a similar distribution can be found in the parts that can not be seen, thereby making an estimate of the total number of candies that could be in the jar if that presumption were true. Estimates can similarly be generated by projecting results from polls or surveys onto the entire population.
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Use String To Estimate Length
Give kids a ball of string and ask them how theyd estimate the length of a piece as tall as they are. Have them cut off the piece of string, then measure their actual height and compare. It will be interesting to see the methods they use and how close they come to getting it right.
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What Is Estimating The Quotient
When we divide two numbers, the result we get is called the quotient. The formula to express the terms of division is divided ÷ divisor = quotient + remainder. It is important to know how to estimate the quotient. Estimating the quotient means, we not doing the division for the actual numbers. You need to round off the dividend and divisor to the nearest 10 and proceed for the division to get the estimated quotient value.
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