Grade 3 Types of data Be able to

Grade 3 Types of data Be able to categorise different types of data, including primary, secondary, discrete, continuous If you have any questions regarding these resources or come across any errors, please contact helpful-report@pixl. org. uk

Key Vocabulary Discrete Continuous Primary Secondary Qualitative Quantitative

Classifying data Data can be classified in several different ways. If you can give something a number (counting or measuring) it is called Quantitative data Example: How many pets do you have? “ 4” If you can’t give something a number it is called Qualitative data Example: What’s your favourite food? “curry”

Quantitative data can be divided into 2 types; Discrete data is counted. Example: How many DVDs do you have? “ 44” Continuous data is measured. Example: What do you weigh? “ 87 kg”

Continuous data You can never measure anything exactly – you need to know how accurate you need to be Example: How tall are you? “ 183 cm” to the nearest cm. Or you could give your answer more accurately. “ 182. 8 cm” to the nearest mm

Collecting data Another way of classifying data is to classify it by the method of collection. Primary data is data collected by you (or under your direction) Secondary data is data collected by someone else. Important sources are books, newspapers, government reports and the internet.

Advantages & disadvantages

Now try these…… 1. State whether the following types of data are qualitative, discrete or continuous. (a) The number of goals scored in a Premier League game (b) Your weight (c) Your favourite type of music (d) The length of a hockey field (e) The number of brothers and sisters you have (f) The score when you throw three dice (g) The colour of cars passing my house

Now try these…… 1. State whether the following types of data are qualitative, discrete or continuous. (a) The number of goals scored in a Premier League game Discrete (b) Your weight Continuous (c) Your favourite type of music Qualitative (d) The length of a hockey field Continuous (e) The number of brothers and sisters you have Discrete (f) The score when you throw three dice Discrete (g) The colour of cars passing my house Qualitative

Problem Solving and Reasoning Doreen collected data by asking people to fill in a questionnaire. Was this primary or secondary data? Colleen collected data from the internet. Was this primary or secondary data? Do we know how accurate Doreen’s data was? Give a reason. Do we know how accurate Colleen’s data was? Give a reason.

Problem Solving and Reasoningsolutions Doreen collected data by asking people to fill in a questionnaire. Was this primary or secondary data? Primary data Colleen collected data from the internet. Was this primary or secondary data? Secondary data Do we know how accurate Doreen’s data was? Give a reason. Accurate data – Doreen collected it herself Do we know how accurate Colleen’s data was? Give a reason. We don’t know how accurate the data is – we don’t know how or when it was collected

Reason and explain What is the difference between primary and secondary data? If I count something, is it discrete or continuous? If I measure something , is it discrete or continuous? Give an example of qualitative data.

Reason and explain What is the difference between primary and secondary data? Primary data is collected by yourself, or under your direction. Secondary data is collected by someone else If I count something, is it discrete or continuous? Discrete If I measure something , is it discrete or continuous? Continuous Give an example of qualitative data. Eg colour of front door, type of clothes you wear

Grade 3 Charts and diagrams Interpret and construct charts and diagrams (including bar charts, pictograms and frequency diagrams) for categorical data If you have any questions regarding these resources or come across any errors, please contact helpful-report@pixl. org. uk

Bar charts are one method of displaying data when the data is categorical (categorical data is another way of saying qualitative data – they are the same thing). The outcomes are marked at equal intervals along the x-axis. The frequency is marked up the y-axis.

Bar Chart Example A woman surveyed the type of vehicle passing her house. The results were given in the table below Car 5 Van 7 Lorry 3 Caravan 1 She decided to draw a bar chart to display this data.

Bar Chart Example Car 5 Van 7 Lorry 3 Caravan 1 Note that the gap between values on the x-axis is always the same size, and the bars are the same thickness.

Now try these…… 1. Draw a bar chart for the following data: Colour of cars White Red Black Blue Other Frequency 5 8 3 4 1

Now try these……solution 1. Draw a bar chart for the following data: Frequency 9 8 7 6 5 4 3 2 1 0 White Red Black Blue Other

Reason and explain How do the gaps differ on the x-axis of a bar chart? The gaps are always the same size What type of data do you use a bar chart for? Categorical data How thick must the bars be on a bar chart? Any suitable thickness to fit on the page. The bars must all be the same thickness however

Grade 3 Pie charts Interpret and construct pie charts for categorical data If you have any questions regarding these resources or come across any errors, please contact helpful-report@pixl. org. uk

Key Vocabulary Pie chart Categorical data Qualitative data Discrete data Proportion Fraction

Pie charts are most usefully used when data is categorical (qualitative) or discrete. They are an alternative method to display data than Bar Charts and Vertical line charts. We draw a circle and split up the areas into the same ratio as the information we are representing.

Example 1 Jerry decides to count the colour of cars passing his house. The results are given below. Colour of car Frequency Lemon Blue Damson 4 6 8 Draw a pie chart of the results.

Example 1 •

Example 1 • Now we are ready to draw our pie chart. We have: Colour Lemon Blue Damson Frequency 4 6 8 Angle of sector 80 120 160 • First draw a circle and mark the centre.

Example 1

Example 1 Now draw a vertical line from the centre to the circumference.

Example 1 Now draw a vertical line from the centre to the circumference.

Example 1 Now carefully measure the angle of the first section, 80∘, and draw in a line to mark this.

Example 1 Now carefully measure the angle of the first section, 80 o, and draw in a line to mark this.

Example 1 Do the same with the other sections:

Example 1 Do the same with the other sections:

Example 1 Finally, label the sectors:

Example 1 Finally, label the sectors: Lemon Damson Blue

Example 2 Sometimes we are given the pie chart, and asked to answer questions about it. The following pie chart was used to display the data from a survey taken amongst a group of Y 10 students

Example 2 What is the most popular food? Favourite food Pizza Curry Burger Healthy The largest slice is ‘Burger’ so that is the most popular food.

Example 2 What is the least popular food? Favourite food Pizza Curry Burger Healthy ‘Healthy’ is the smallest slice, so the least popular food.

Example 2 • Favourite food Pizza Curry Burger Healthy

Now try these…… 1. Draw a pie chart for the following survey of 60 people’s favourite type of tv programme. TV Programme Frequency Drama 12 Sport 30 News 6 Other 12

Now try these…. . 2. The following questions are about this pie chart: (a) Which was the most popular destination? (b) Which two destinations were equally popular? (c) Which was the least popular destination?

Now try these……solutions 1. Draw a pie chart for the following survey of 60 people’s favourite type of tv programme. 360 ÷ 60 = 6 TV Programme Frequency Angle Drama 12 12 x 6 = 72 Sport 30 30 x 6 = 180 News 6 6 x 6 = 36 Other 12 12 x 6 = 72 Total 60

Now try these……solutions 1. Draw a pie chart for the following survey of 60 people’s favourite type of tv programme. 360 ÷ 60 = 6

Now try these…. . solutions 2. The following questions are about this pie chart: (a) Which was the most popular destination? Greece (b) Which two destinations were equally popular? America and Spain (c) Which was the least popular destination? France

Reason and explain How many degrees are there if you turn through a full circle? 360 o What type of data do you use a pie chart for? Qualitative (categorical) data How do the sectors of a pie chart relate to the frequency? The area is in the same ratio as the frequency