📝 Student Worksheet — Session 3: Collecting Data

Data Science for Young Minds · Grade 3 · Ages 8–9

Name

Date

Class Period

📚 Part 1 — Vocabulary

Survey

Observation

Measurement

Tally mark

Consistency

Data collection error

✏️ Part 2 — Tally Mark Practice

Remember: the 5th mark crosses through the group of 4.

| | | | | | | | | | ||||̶ ||||̶ | = 1, 2, 3, 4, 5, 6…

Draw tally marks for each number:

Number	Draw Your Tally Marks Here
7
12
5
18

Count these tally marks and write the number:

Tally Marks	Count =
\|\|\|\|̶ \| \|
\|\|\|\|̶ \|\|\|\|̶ \| \| \|
\| \| \| \|

🔬 Part 3 — Match the Method

For each situation, write Survey, Observation, or Measurement in the box.

Situation	Best Method
You want to know how long each student's pencil is.
You want to know how many birds visit the feeder each morning.
You want to know which school lunch students prefer.
You want to find out how many books are on the classroom shelf.
You want to know how tall five different plants have grown.
You want to know what color jacket most students are wearing today.

📊 Part 4 — My Mini-Survey Recording Sheet

My survey question (from Session 2):

Number of people I will ask:

Use tally marks to record each answer as you ask:

Answer Choice	Tally Marks (make a mark each time someone says this)	Total

Grand total responses: Most popular answer:

✅ Survey Checklist: Did I ask the question exactly as written? ☐ Yes Did I record immediately? ☐ Yes Did I ask each person only once? ☐ Yes

🔍 Part 5 — Error Detective

Read each story. Circle the mistake and explain what the data collector should have done differently.

🔎 Scenario 1

Mia is collecting data about favorite colors. For the first 5 people she writes the color names (like "blue" or "red"). For the last 5 people, she uses tally marks instead. When she tries to count her results, everything is mixed up.

What is the error?

What should Mia have done?

🔎 Scenario 2

Sam is asking classmates "What is your favorite sport?" But every time he asks, he adds "…most people say soccer, just so you know!" before they answer.

What is the error?

What should Sam have done?

🔎 Scenario 3

Dev needs to survey 10 people. He surveys 9 people, then realizes he forgot to count his best friend's answer — so he goes back and adds it. But he had already asked his best friend at the beginning!

What is the error?

What should Dev have done?

✍️ Part 6 — Think About It

Why is it important to use the same recording method for ALL your answers?

Which of the three collection methods (survey, observation, measurement) do you think is hardest to do correctly? Why?

After doing your mini-survey today, what is one thing you would do differently next time?

🏠 Take-Home Challenge — Be a Data Collector!

Pick ONE thing to observe or count at home this week. Record your data using tally marks!

What I'm counting or observing:

My collection method: ☐ Survey ☐ Observation ☐ Measurement

My tally results:

Category	Tally Marks	Total

What surprised you about what you found?