# Compound Units

## Practise using compound units such as speed, unit pricing and density to solve problems.

##### Level 1Level 2Level 3Exam-StyleDescriptionHelpMore Mensuration

This is level 3; Solving problems involving compound units. You can earn a trophy if you get at least 4 questions correct.

 The speed on a particular road in the UK is 70 mph. What is this speed expressed in kilometres per hour if 1 mile = 1.6 km? km/h A sprinter runs a 100 metre race in 18 seconds. What is the sprinter's average speed in km/h? Give your answer to three significant figures. km/h How many kilograms of soap powder should be added to 11 litres of water if the concentration should be 74 grams per centilitre? kg In a UK supermarket sugar was on sale for 55p per kilogram bag. In an American convenience store sugar was being sold in a different way. For \$1 you could get 824g. If the exchange rate was £1 = \$1.60 by how many pennies is a kilogram of sugar cheaper in the UK? Give your answer to the nearest whole number. pence The numerical value of the density of an cube, expressed in kilograms per cubic metre, is equal to its surface area expressed in square centimetres. If each edge of the cube is of length 10cm, what is its mass? Give your answer to three significant figures. kg
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This is Compound Units level 3. You can also try:
Level 1 Level 2

## 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.

## Transum.org

This 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.

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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?

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#### ChrisMaths

Christmas activities make those December Maths lessons interesting, exciting and relevant. If students have access to computers there are some online activities to keep them engaged such as Christmas Ornaments and Christmas Light Up.

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## 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:

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## Description of Levels

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Level 1 - Using simple compund units in calculations

Level 2 - Converting between one compound unit and another

Level 3 - Solving problems involving compound units

## Useful Information

mph stands for miles per hour

km/h stands for kilometers per hour

Distance = Speed x Time

Mass = Density x Volume

Pressure = Force ÷ Area

There are 100 centilitres in a litre

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