Rough AnswersAn exercise on rounding values in a calculation to find an approximate estimate of the answer. 
This is level 1: round the numbers in a basic calculation to one significant figure to obtain an approximate answer. You will be awarded a trophy if you get at least 9 correct and you do this activity online.
InstructionsTry your best to answer the questions above. Type your answers into the boxes provided leaving no spaces. As you work through the exercise regularly click the "check" button. If you have any wrong answers, do your best to do corrections but if there is anything you don't understand, please ask your teacher for help. When you have got all of the questions correct you may want to print out this page and paste it into your exercise book. If you keep your work in an ePortfolio you could take a screen shot of your answers and paste that into your Maths file. 



Transum.orgThis web site contains over a thousand free mathematical activities for teachers and pupils. Click here to go to the main page which links to all of the resources available. Please contact me if you have any suggestions or questions. 
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Mathematicians are not the people who find Maths easy; they are the people who enjoy how mystifying, puzzling and hard it is. Are you a mathematician? Comment recorded on the 10 April 'Starter of the Day' page by Mike Sendrove, Salt Grammar School, UK.: "A really useful set of resources  thanks. Is the collection available on CD? Are solutions available?" Comment recorded on the 18 September 'Starter of the Day' page by Mrs. Peacock, Downe House School and Kennet School: "My year 8's absolutely loved the "Separated Twins" starter. I set it as an optional piece of work for my year 11's over a weekend and one girl came up with 3 independant solutions." 
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AnswersThere are answers to this exercise but they are available in this space to teachers, tutors and parents who have logged in to their Transum subscription on this computer. A Transum subscription unlocks the answers to the online exercises, quizzes and puzzles. It also provides the teacher with access to quality external links on each of the Transum Topic pages and the facility to add to the collection themselves. Subscribers can manage class lists, lesson plans and assessment data in the Class Admin application and have access to reports of the Transum Trophies earned by class members. If you would like to enjoy adfree access to the thousands of Transum resources, receive our monthly newsletter, unlock the printable worksheets and see our Maths Lesson Finishers then sign up for a subscription now: Subscribe 

Go MathsLearning and understanding Mathematics, at every level, requires learner engagement. Mathematics is not a spectator sport. Sometimes traditional teaching fails to actively involve students. One way to address the problem is through the use of interactive activities and this web site provides many of those. The Go Maths page is an alphabetical list of free activities designed for students in Secondary/High school. Maths MapAre you looking for something specific? An exercise to supplement the topic you are studying at school at the moment perhaps. Navigate using our Maths Map to find exercises, puzzles and Maths lesson starters grouped by topic.  
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If you found this activity useful don't forget to record it in your scheme of work or learning management system. The short URL, ready to be copied and pasted, is as follows: 
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© Transum Mathematics :: This activity can be found online at:
www.transum.org/Maths/Exercise/Approximating/Default.asp
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Rounding  Before doing these exercises you will need to know how to round numbers to one significant figure.
Level 1  Round the numbers in a basic calculation to one significant figure to obtain an approximate answer
Level 2  Round the numbers to one significant figure to obtain an approximate answer to calculations including decimals and fractions
Level 3  Determine whether an approximation is a overestimate or an underestimate if each of the numbers are rounded to one significant figure
Level 4  Real life problems and puzzles
Bounds  Determine the upper and lower bounds when rounding or truncating quantities used in calculations.
Exam Style Questions  A collection of problems in the style of GCSE or IB/Alevel exam paper questions (worked solutions are available for Transum subscribers).
Breathe Easily  A reallife question that can be (roughly) answered by making some approximations.
Fermi Problem  Unleash your approximating skills to estimate something quite unknown in this Advanced Starter.
More on this topic including lesson Starters, visual aids, investigations and selfmarking exercises.
Answers to this exercise are available lower down this page when you are logged in to your Transum account. If you don’t yet have a Transum subscription one can be very quickly set up if you are a teacher, tutor or parent.
See the National Curriculum page for links to related online activities and resources.
The video above is from the maths520 channel.
Don't wait until you have finished the exercise before you click on the 'Check' button. Click it often as you work through the questions to see if you are answering them correctly. You can doubleclick the 'Check' button to make it float at the bottom of your screen.
Answers to this exercise are available lower down this page when you are logged in to your Transum account. If you don’t yet have a Transum subscription one can be very quickly set up if you are a teacher, tutor or parent.
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Jen, Australia
Saturday, June 1, 2019
"I just tried level one. It looks like a great way to reinforce significant figures to students, through mental estimates! However, the question says give answers to one significant figure  and I just got most of the questions "wrong", as your answers are mostly to 2 significant figures."
Transum,
Sunday, June 2, 2019
"Thanks very much for your feedback Jen. The instructions ask for the numbers in the questions to be rounded to one significant figure; not the answers. The answers should be given exact after the precalculation rounding has taken place. Once again thanks for the feedback, much appreciated."