# Percentage Change

## Practise calculating percentage increase and percentage decrease in this set of exercises.

##### MenuLevel 1Level 2Level 3Level 4Level 5Level 6Level 7SwitchExamHelpMore

This is level 7: challenging questions. You can earn a trophy if you get at least 7 questions correct. You can use a calculator.

Give non-exact answers to three significant figures.

 1. At the end of May the resevoir was seven-eigths full. By the middle of August it was only one quarter full. Calculate the percentage decrease in the amount of water in the resevoir between the end of May and the middle of August. % 2. I have been exercising for three hours and forty minutes each week. Next week I plan to spend five hours exercising. By what percentage will I be increasing my excercise time? % 3. A shrub was five feet tall. A gardener pruned it, reducing its height by 35%. How many inches tall is the shrub now? in 4. Alan's weight increased in 2022 by 22%. Last year Alan adopted a more healthy lifestyle and his weight returned to what it was at the beginning of 2022. What was the percentage decrease from his heaviest weight back to his previous weight? % 5. A circle's radius is increased by 21%. Find the percentage increase in the circle's area. % 6. A circle's area is increased by 26%. Find the percentage increase in the circle's radius. % 7. The lengths of the edges of a cube are all increased by 15%. Find the percentage increase in the cube's volume. % 8. A cube's volume is increased by 9%. Find the percentage increase in the lengths of the cube's edges. % 9. Find A if 30% of A equals 30% of 30 plus 30. 10. Allan sold a painting to Bella. Bella then sold the painting to Chris who, in turn sold the painting to Dally. The price increased overall by 90% of what it was originally worth.If Allan made 40% profit and Bella made 20% profit, what percentage profit did Chris make? %
Check

This is Percentage Change level 7. You can also try:
Level 1 Level 2 Level 3 Level 4 Level 5 Level 6

## Instructions

Try 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.

## More Activities:

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 19 November 'Starter of the Day' page by Lesley Sewell, Ysgol Aberconwy, Wales:

"A Maths colleague introduced me to your web site and I love to use it. The questions are so varied I can use them with all of my classes, I even let year 13 have a go at some of them. I like being able to access Starters for the whole month so I can use favourites with classes I see at different times of the week. Thanks."

Comment recorded on the 16 March 'Starter of the Day' page by Mrs A Milton, Ysgol Ardudwy:

"I have used your starters for 3 years now and would not have a lesson without one! Fantastic way to engage the pupils at the start of a lesson."

Each month a newsletter is published containing details of the new additions to the Transum website and a new puzzle of the month.

The newsletter is then duplicated as a podcast which is available on the major delivery networks. You can listen to the podcast while you are commuting, exercising or relaxing.

Transum breaking news is available on Twitter @Transum and if that's not enough there is also a Transum Facebook page.

#### Number Crunch Saga

A lively numeracy game requiring you to align three numbers to create the given target sum or product. There are five levels to this online game and a virtual Transum Trophy available for each level.

There 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.

Subscribe

## Go Maths

Learning 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 Map

Are 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.

## Teachers

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:

Alternatively, if you use Google Classroom, all you have to do is click on the green icon below in order to add this activity to one of your classes.

It may be worth remembering that if Transum.org should go offline for whatever reason, there is a mirror site at Transum.info that contains most of the resources that are available here on Transum.org.

When planning to use technology in your lesson always have a plan B!

Do you have any comments? It is always useful to receive feedback and helps make this free resource even more useful for those learning Mathematics anywhere in the world. Click here to enter your comments.

For Students:

For All:

Scan the QR code below to visit the online version of this activity.

https://www.Transum.org/go/?Num=342

## Description of Levels

Close

Simple Percentages - A good place to start.

Level 1 - Find the new amount after a percentage increase.

Level 2 - Find the new amount after a percentage decrease.

Level 3 - Find the percentage increase given the original and final values.

Level 4 - Find the percentage decrease given the original and final values.

Level 5 - Find the original amount after a percentage increase or decrease given the final value.

Level 6 - Mixed questions.

Level 7 - Challenging questions.

Switch - Practise percentage increase and decrease calculations by completing this table.

Exam Style questions are in the style of GCSE or IB/A-level exam paper questions and worked solutions are available for Transum subscribers.

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.

## Curriculum Reference

See the National Curriculum page for links to related online activities and resources.

## Example

You may want to use a calculator for some of the questions. See Calculator Workout skill 3.

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.

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.

Close