Chapter 7 of 7

All 7 chapters
  1. 1Tally and frequency tables, readunderstood
  2. 2Pictograms with a key, readunderstood
  3. 3Bar charts, readunderstood
  4. 4Tables with rows and columns, readunderstood
  5. 5Sorting diagrams, readunderstood
  6. 6Line graphs, readunderstood
  7. 7Your own survey, readunderstood

M2.7.7 Chapter 7

Your own survey

I asked my friends a question. What do I do with their answers?

Your guess

Pick one before you read on. It is fine to be wrong.

Your guess

  • You picked A. Read on. At the end, the chapter comes back to your guess.

  • You picked B. Read on. At the end, the chapter comes back to your guess.

  • You picked C. Read on. At the end, the chapter comes back to your guess.

By the end you can

  • Ask a question, collect data and choose a chart to show it
  • Write two true sentences about what a chart shows

Mei wants to know how people get to school. She asks 20 people one question.

This is a survey. You ask many people the same question. Their answers are data.

A good question has a few clear choices. Each person picks one choice.

Draw it first

From a question to a chart

  1. Step 1 shows the question How do you get to school? with the choices walk, bus, bike and car. Step 2 adds tally marks for each choice: 9 for walk, 5 for bus, 4 for bike and 2 for car. Step 3 shows a table with the heads travel and people. The rows are walk 9, bus 5, bike 4, car 2 and total 20. Step 4 shows a bar chart with the label people and bars for walk, bus, bike and car.How do you get to school?walkbusbikecar

    1 Ask one question. Give a few choices, such as walk, bus, bike and car.

  2. Step 1 shows the question How do you get to school? with the choices walk, bus, bike and car. Step 2 adds tally marks for each choice: 9 for walk, 5 for bus, 4 for bike and 2 for car. Step 3 shows a table with the heads travel and people. The rows are walk 9, bus 5, bike 4, car 2 and total 20. Step 4 shows a bar chart with the label people and bars for walk, bus, bike and car.How do you get to school?walkbusbikecar

    2 Ask each person. Make one tally mark for each answer.

  3. Step 1 shows the question How do you get to school? with the choices walk, bus, bike and car. Step 2 adds tally marks for each choice: 9 for walk, 5 for bus, 4 for bike and 2 for car. Step 3 shows a table with the heads travel and people. The rows are walk 9, bus 5, bike 4, car 2 and total 20. Step 4 shows a bar chart with the label people and bars for walk, bus, bike and car.How do you get to school?travelpeoplewalk9bus5bike4car2total20

    3 Count the tallies. Write the counts in a table. Add them to find the total.

  4. Step 1 shows the question How do you get to school? with the choices walk, bus, bike and car. Step 2 adds tally marks for each choice: 9 for walk, 5 for bus, 4 for bike and 2 for car. Step 3 shows a table with the heads travel and people. The rows are walk 9, bus 5, bike 4, car 2 and total 20. Step 4 shows a bar chart with the label people and bars for walk, bus, bike and car.How do you get to school?0246810walkbusbikecarpeople

    4 Draw a bar chart. Each bar shows how many people chose that way.

Check your counts. They must add up to the number of people you asked.

Worked example

Mei asked 20 people. Do her counts add up to 20?

  1. Add the counts. 9 + 5 = 14.
  2. Then 14 + 4 = 18.
  3. Then 18 + 2 = 20.

Answer: Yes. The counts make 20, and 20 people were asked.

Now pick the chart. Look at your data first. The data tells you which chart fits.

A table with the heads data about and best chart. Choices use a bar chart. Over time uses a line graph. Two rules use a 2 by 2 table.data aboutbest chartchoicesbar chartover timeline graphtwo rules2 by 2 table
A pictogram also shows choices. It works well when the counts are small.

Mei asked about choices. So she uses a bar chart. Here it is.

A bar chart with the label people. The bars are walk 9, bus 5, bike 4 and car 2. The question was How do you get to school?0246810walkbusbikecarpeople
Mei's chart. Use it to write sentences.

Now say what the chart shows. Write only what you can see. Use a name and a number from the chart.

Worked example

Write two true sentences about Mei's chart.

  1. Find the tallest bar. It is walk, with 9.
  2. Compare two bars. Walk is 9. Bike is 4. 9 − 4 = 5.
  3. Write what you see. Use the names and numbers.

Answer: More people walk than use any other way. 5 more people walk than ride a bike.

See it three ways

With things

Ask 10 people: tea, water, juice or milk? Put a stone in a row for each answer.

As a picture

A pictogram of 10 answers. The rows are tea, water, juice and milk, with 4, 3, 2 and 1 symbols. The key says each symbol = 1.teawaterjuicemilkeach= 1

In symbols

4 + 3 + 2 + 1 = 10. Tea has 4. Milk has 1. Tea has 3 more than milk.

Try it

Run a survey of 10 people

You need: paper and a pencil, 10 people to ask, at home or nearby.

  1. Pick a question with 3 or 4 choices. Write the choices on paper.
  2. Ask 10 people. Each person picks one choice. Make a tally mark.
  3. Count each tally. Add the counts. The total must be 10.
  4. Pick a chart that fits. Choices fit a bar chart.
  5. Draw it with a title. Write two true sentences under it.

What you will see: Your counts add up to 10. Your sentences use only names and numbers from the chart.

If you cannot try it, this is what happens.
A bar chart with the title Which fruit do you like best? and the label people. The bars are mango 5, guava 3 and lime 2. Together they make 10 people.Which fruit do you like best?0246mangoguavalimepeople

A wrong idea many people have

My chart shows why people choose each way.

Why it feels right: You know your friends. You may want to fill in the reason yourself.

The test that breaks it: Ask three of the nine walkers why they walk. You may get three different reasons. The chart has none of them.

What is true: A chart shows what people chose and how many. It does not show why. Write only what the chart shows.

Key words

survey
asking many people the same question.
data
the answers you collect.

Back to your guess

The answer is B: Tally them, then draw the chart that fits.

Tally the answers and check the total. Then pick the chart that fits the data. Say only what it shows.

Check yourself

Try each one before you look. A wrong answer tells you where to go next.

  1. Tariq measures the water in his tank each day. Which chart fits best?

    Tap your answer.

    1. Not this one. A pictogram counts choices. The water changes day by day. Use a line graph. Go to M2.7.6. Try another.

    2. Yes, that is right. The water level changes as the days pass. A line graph shows change over time.

    3. Not this one. A Venn diagram sorts by two rules. It does not show change over time. Go to M2.7.5. Try another.

    See the answer

    A line graph

    The water level changes as the days pass. A line graph shows change over time.

    • If you chose A: A pictogram counts choices. The water changes day by day. Use a line graph. Go to M2.7.6.
    • If you chose C: A Venn diagram sorts by two rules. It does not show change over time. Go to M2.7.5.

  2. Lucía asks 30 people which colour they like best. Which chart fits best?

    Tap your answer.

    1. Not this one. A line graph shows change over time. Colours are choices, not days. Go to M2.7.6. Try another.

    2. Not this one. A 2 by 2 table sorts by two rules. Lucía has one question with many choices. Go to M2.7.5. Try another.

    3. Yes, that is right. Colours are choices. Either one shows how many people chose each colour.

    See the answer

    A bar chart or a pictogram

    Colours are choices. Either one shows how many people chose each colour.

    • If you chose A: A line graph shows change over time. Colours are choices, not days. Go to M2.7.6.
    • If you chose B: A 2 by 2 table sorts by two rules. Lucía has one question with many choices. Go to M2.7.5.

  3. Look at Mei's chart. Which sentence is true?

    A bar chart with the label people. The bars are walk 9, bus 5, bike 4 and car 2. The question was How do you get to school?0246810walkbusbikecarpeople
    Tap your answer.

    1. Yes, that is right. Walk is 9 and bus is 5. 9 is more than 5.

    2. Not this one. The chart does not show why. Write only what you can see on it. Try another.

    3. Not this one. Read the bus bar again. It reaches 5. The bike bar is 4. Go to M2.7.3. Try another.

    See the answer

    More people walk than ride the bus.

    Walk is 9 and bus is 5. 9 is more than 5.

    • If you chose B: The chart does not show why. Write only what you can see on it.
    • If you chose C: Read the bus bar again. It reaches 5. The bike bar is 4. Go to M2.7.3.

  4. Ana asks 12 children their favourite colour. Her tally says red 5, blue 4, green 2. How many answers are missing?

    See the answer

    1

    5 + 4 + 2 = 11. She asked 12. 12 − 11 = 1. Find the missing answer and count again.

  5. Look at the chart. Write two true sentences about it.

    A bar chart with the label people. The question is Which pet would you like? The bars are dog 9, cat 6, fish 3 and bird 2.Which pet would you like?0246810dogcatfishbirdpeople
    See the answer

    Dog is the top choice, with 9 people. 3 more people chose cat than fish.

    Any sentence is right if you can check it on the chart. Use a name and a number. Do not say why.

  6. From an earlier chapter

    Each symbol is worth 2 people. A half symbol is worth 1 person. How many people take the bus?

    A pictogram with the rows walk, bus and bike. The key says each symbol = 2. Walk has 4 whole symbols. Bus has 3 whole symbols and 1 half symbol. Bike has 1 whole symbol and 1 half symbol.walkbusbikeeach= 2
    See the answer

    7

    3 whole symbols are 3 × 2 = 6. The half symbol is 1. 6 + 1 = 7.

  7. Ravi wants to survey his class about games. Which is the best question to ask?

    Tap your answer.

    1. Not this one. People could answer about anything: food, games, colours. The answers will not sort into a few rows. The tally tells you little. Try another.

    2. Not this one. That is two questions. Ask one question, so each person gives one answer. Try another.

    3. Yes, that is right. It is one question with a few clear choices. Each person picks one, so you can tally the answers.

    See the answer

    Which game do you like best: tag, ball or rope?

    It is one question with a few clear choices. Each person picks one, so you can tally the answers.

    • If you chose A: People could answer about anything: food, games, colours. The answers will not sort into a few rows. The tally tells you little.
    • If you chose B: That is two questions. Ask one question, so each person gives one answer.

  8. Look at the pet chart. Which sentence is true?

    A bar chart with the label people. The question is Which pet would you like? The bars are dog 9, cat 6, fish 3 and bird 2.Which pet would you like?0246810dogcatfishbirdpeople
    Tap your answer.

    1. Not this one. The dog bar is 9, but that is one bar. Add all four bars to find how many were asked. Try another.

    2. Yes, that is right. Dog is 9 and cat is 6. 9 − 6 = 3. The four bars add to 20, not 9. The chart does not say why.

    3. Not this one. The chart shows what people chose. It does not show why they chose it. Try another.

    See the answer

    3 more people chose dog than cat.

    Dog is 9 and cat is 6. 9 − 6 = 3. The four bars add to 20, not 9. The chart does not say why.

    • If you chose A: The dog bar is 9, but that is one bar. Add all four bars to find how many were asked.
    • If you chose C: The chart shows what people chose. It does not show why they chose it.

Keep it

Copy this into your exercise book.

Ask one question with clear choices. Tally the answers. Check the counts add up to the people asked. Pick the chart by the data. Bars fit choices. A line fits time. Write only what the chart shows.

Draw: A table of counts, then a bar chart with a title. Write two true sentences under it.

Reading with a child? A short page for the adult: what this chapter teaches and three questions to ask.

No internet tomorrow? Save the whole book as one file (828 KB). It opens on any phone.