Reading Scales (SQA National 5 Applications of Mathematics): Revision Note

Reading scales

How do I find the small divisions on a scale?

• You will be given at least two values on a scale

  • The gap between them will be split into scale divisions

• STEP 1
  Find the difference between any pair of values on the scale

• STEP 2
  Count the number of scale divisions between the pair of values

  • Usually there are 5, 10 or 20 divisions

• STEP 3
  Divide the difference between the pair by the number of scale divisions

  • This tells you how much each scale division is worth

How do I read a scale?

• STEP 1
  Find the value of each scale division

• STEP 2
  Identify the direction of the scale

  • Use the direction in which the numbers are increasing

• STEP 3
  Count the number of scale divisions from the last major division

  • There are normally major divisions at multiples of 10 or 20

• STEP 4
  Use the value of each scale division to find the value

How do I use measuring equipment with two units?

• Some measuring tools include two different units

• Examples include

  • thermometers which measure using degrees Celsius and degrees Fahrenheit

  • pressure gauges which measure using kPa and psi

  • speedometers which measure using mph and km/h

• Treat each scale separately and find the values of their scale divisions

• You can use these measuring devices to:

  • convert between units

  • compare two measurements using different units