Back to Ganita Prakash: Class 7 Mathematics, Par...BackConcept

Be A Data Collector: Projects With Your Own Data

Plan, collect, show and summarise your own data: estimating lengths, sentence lengths, names, and how long a minute feels.

5 micro-lessons

Preview · progress not saved — Chapter 1 is free

Running a Data Project

Ask, collect, organise, show and describe.

Five steps (Textbook pp. 131–134)

Ask a statistical question.
Collect enough data: 7 or more values, and the more the better.
Organise it in a table.
Show it: a dot plot for one set of values, a double bar graph to compare two groups.
Describe it: minimum, maximum, spread, mean, median, and anything surprising.

Estimate, Then Measure

A worked version of the estimate-vs-measure project.

Problem. Estimate, then measure, five objects. How accurate were your estimates? (Textbook pp. 131–132, Q9)

These are sample numbers to show the method. Use your own for the activity below.

1 / 5

Your Project Checklist

Five parts every data report needs.

Every data report needs

1. A question.

2. A data table.

3. A plot: a dot plot or a double bar graph.

4. A summary: min, max, range, mean, median.

5. One observation or surprise, and a new question it raises.

Your Estimate Challenge

Estimate and measure five objects and analyse your accuracy.

Estimate, measure and compare

Figure it Out, Textbook p. 131, Q9. Estimate, then measure, the length of: a pen, an eraser, your palm, your geometry box and your maths notebook. Draw a double bar graph on paper. How accurate were your estimates?

Your five estimates and measurements (cm)

Object: estimate, measure.

Positive differences and their average

Bigger − smaller for each.

Which estimate was best, and which worst?

Any pattern, e.g. always too short?

Choose a Project

Pick one project and report your findings.

Do a project and report

Figure it Out, Textbook pp. 130–134. Pick at least one:

Q6 Heights of your class: mean, median and a dot plot.
Q11(a) How long is a sentence? Words per sentence on a text-heavy page from two textbooks of different subjects. Dot plots; compare with mean and median.
Q11(b) What's in a name? Name lengths of your classmates; popular starting letters; the median starting letter; a double bar graph of boys' and girls' names that start and end with vowels or consonants.
Q12 In and Out (long term): how many times you step out of the house each day, for a month.
Q13(a) Your height against your family's heights.
Q13(b) Estimating time: estimate 1 minute and 3 minutes with your eyes closed, for you and your family.

Which project, and your statistical question

Name it.

Your data (or a summary of it)

Enough values to say something.

Min, max, mean and median

Show the working briefly.

Describe your plot

Where do the dots bunch? Any outliers?

One surprise and one new question

What did the data make you wonder?

← previousData Detective Casebook next →Review: Connecting The Dots