Math
The Corner Count
Count the traffic on your own corner in timed windows across three days, chart what you find, then predict the next count before you go and check it.
Easy · 3 x 20 minutes
Introduction
Data does not only live in textbooks. It is out on your street right now, and nobody has written it down yet.
In this project you become the person who writes it down. You pick one spot, count what passes in a fixed window of time, and repeat until a pattern shows up. Then comes the hard part: you predict the next number before you go and count it.
The Why
A pattern you find yourself is worth more than a pattern you are handed. Counting in equal, fixed windows is what makes numbers comparable, and comparing them is what turns a pile of tally marks into a bar chart with something to say. Predicting before you measure is the whole scientific method in twenty minutes: you commit to an answer, then let the real world tell you how close you were.
Step-by-Step Instructions
- 1
Pick one spot you can reach easily and safely, like a window facing the street or a bench set back from the curb. Use the exact same spot every single time.
- 2
Pick three things to count. Cars, people walking, and dogs is a good start, but bikes, buses, or delivery vans work just as well.
- 3
Set your timer for 10 minutes. Every time one of your three things goes past, make one tally mark. When the timer goes off, stop counting, even if something is halfway past.
- 4
Write down the date, the start time, and the weather beside your tallies. Those three notes are what let you compare one window against another later.
- 5
Repeat at the same time of day on two more days, so you finish with three windows you can fairly compare.
- 6
Draw a bar chart with your three things along the bottom and the counts running up the side. Use one color per day so the three days stand side by side.
- 7
Before your fourth count, write down a prediction for each category and one sentence on why you picked that number. Then go and count, and write the real number next to your guess.
Traffic Tally Sheet
Print this and fill in one row per counting window. Keep every window exactly the same length, or the numbers cannot be compared.
| Date | Start time | Weather | Cars | People walking | Dogs |
|---|---|---|---|---|---|
| Row 1, Date | Row 1, Start time | Row 1, Weather | Row 1, Cars | Row 1, People walking | Row 1, Dogs |
| Row 2, Date | Row 2, Start time | Row 2, Weather | Row 2, Cars | Row 2, People walking | Row 2, Dogs |
| Row 3, Date | Row 3, Start time | Row 3, Weather | Row 3, Cars | Row 3, People walking | Row 3, Dogs |
| Row 4, Date | Row 4, Start time | Row 4, Weather | Row 4, Cars | Row 4, People walking | Row 4, Dogs |
Before your last window, write your prediction for each column in the margin. Afterward, circle the one you came closest on.