MATHEMATICSMeasures – Units, Equipment and Scales

Lesson Objectives

•The aim of this powerpoint is to help you…

• Determine the appropriate ‘units’ to measure in, for length, mass & capacity

• Determine the appropriate equipment to use to measure something

• Work out how to interpret different scales

Appropriate measures & equipment

• Given a particular situation you need to decide on two things…

• What units are most appropriate to use to measure in

• What is an appropriate measuring device

What do we measure?

• LENGTH or distance• i.e. How long something is.

• MASS (sometimes called ‘weight’ by mistake)• i.e. How heavy something is.

• CAPACITY (sometimes called ‘volume’)• i.e. How much liquid is contained.

Metric Units for Length

LENGTH• Millimetre [mm] (for very small or thin distances)

• Centimetre [cm] (for short distances up to 2 metres)

• Metre [m] (for distances up to 2 kilometres)

• Kilometre [km] (for longer distances between places)

• Examples of measuring devices for length are…• Rulers, Trundle Wheels, Pedometers, Milometers…

Metric Units for Mass

MASS• Milligram [mg] (for very light weights, e.g. feather)

• Gram [g] (for very small objects, e.g. a coin)

• Kilogram [kg] (for heavier weights, e.g. a person)

• Tonne [T] (for very large, heavy objects, e.g. car)

• Examples of measuring devices for mass are…• Kitchen scales, bathroom scales, weighbridges…

Metric Units for Capacity

CAPACITY• Millilitre [ml] (for most small vessels, e.g. spoon)

• Centilitre [cl] (also for small containers, e.g. bottle)

• Litre [l] (for larger vessels, e.g. petrol tank)

• Examples of measuring devices for capacity are• Syringes, pipettes, measuring jugs, petrol pumps,

teaspoons, tablespoons…

Sample Situation 1

• You wish to measure the time it takes you to walk home from school (a distance of about 1.5 miles)… measures & devices?

• It should take you a time in MINUTES

• A WRISTWATCH would be a suitable device (as opposed to a wall clock or a stopwatch)

Sample Situation 2

• You wish to measure the thickness of a strand of copper wire…measures & devices?

• It should be a length in MILLIMETRES (or more likely a fraction of a millimetre)

• A MICROMETER would be a suitable device (rather than a ruler or tape measure)

SCALES

• When measuring, you need to consider the scale of each larger marking and therefore the value of each smaller marking

• You divide the difference between larger markings by the number of smaller sections there are between them

• Let’s look at 3 examples…

Example 1

• The difference between 3 and 4 is 1.

• Divide this by 10 (smaller sections) and each smaller marking is worth 1 ÷ 10 = 0.1

• The arrow is pointing at 3 + (4×0.1) = 3.4

3 4 5 6

Example 2

• The difference between 3.5 and 4 is 0.5

• Divide this by 10 (smaller sections) and each smaller marking is worth 0.5 ÷ 10 = 0.05

• The arrow is pointing at 3.5 + (6×0.05) = 3.8

3 3.5 4 4.5

Example 3

• The difference between 9.1 and 9.2 is 0.1

• Divide this by 5 (smaller sections) and each smaller marking is worth 0.1 ÷ 5 = 0.02

• The arrow is pointing at 9.1 + (4×0.02) = 9.18

9 9.1 9.2 9.3

What next?• Print out the notes called Meas1. Read through them and

make sure you answer any questions.

• Work through the following MyMaths lessons: • Units of Length: http://app.mymaths.co.uk/293-resource/units-of-length

• Units of Mass: http://app.mymaths.co.uk/294-resource/units-of-mass

• Units of Capacity: http://app.mymaths.co.uk/295-resource/units-of-capacity

• Save and complete the worksheets: • Meas-S1.xlsx & Scales-S1.xlsx

• Now move on to the Meas2a powerpoint