How to Read Scales | GCSE Maths Success
Introduction
There are a number of different scales that you will have come across. These will include the scale on a thermometer, a cars speed dial and even scales that are used to weight people.
A scale is usually shown by a line with small increments. It is important that when it comes to reading a scale you are able to determine what each division actually represents.
You should also make sure that you can read the scale in the right direction as some scales read up and down (such as that of a thermometer) and some are even circular such as those on weighting scales.
Make sure also that you are aware of the units as it is quite likely to include the units within your answer.
How to read scales - example 1
Example
Take a look at the following question:
Here you can see that the numbers are increasing by 10 and if you count the number of “smaller lines” between each number there are a total of 10. These little lines represent a division so this means that each division has a value of 1.
Counting from 40, until the location of the arrow, there are 6 divisions, so the value required will be 46.
How To Read Scales - Example 2
Take a look at the following question:
In this question you need to label where 430 is with an arrow. From the scale you can see that the numbers are increasing by 100 and that between each number there is a total of 10 divisions. This means that each division will have a value of 10.
So to find 430, from 400 you need to place the arrow at the third division as shown below:
How to read scales – example 3
Take a look at the following question:
In this instance you are asked to show a value that contains a decimal. From the scale you can see that the numbers are increasing by 1 and between each number there are 10 divisions. This will mean that each division will have a value of 0.1 (1 ÷ 10 = 0.1).
From 3, you will then need to count 7 divisions and place the arrow as shown below:
How To Read Scales – Question Practice
Try the following questions on your own before looking at the solution:
Question Practice Solution
You will notice in this question that the numbers are increasing by 10 and there are only two divisions. So the line shown in the middle must be the half way point.
The number marked with the arrow will be 75.
Question Practice
Try the following questions on your own before looking at the solution:
Question Practice Solution
Here the numbers on the scale are increasing by 100 and between each number there are 10 divisions so each division has a value of 10.
From 500, count 3 divisions to the right and then place the arrow as shown below:
Question Practice
Try the following questions on your own before looking at the solution:
Question Practice Solution
This is the type of scale that you could see on a weighing scale. So far you have generally seen scales that are horizontal but here the scale is circular. However the process is exactly the same.
On the scale the numbers are increasing by 1 and there are 10 divisions between each number. Each division will have a value of 0.1 (1 10 = 0.1).
The reading of the scale will be 3.8kg.
Remember, in this type of question something is actually being weighed so a unit must be included in the answer.
Provided you can determine what the actual scale is, then reading scales is quite an easy topic to get full marks .