📋 Activity Overview

Students receive 30 'census cards' (name, age, occupation, village, income) and must answer 5 questions as quickly as possible — discovering that how you organise data changes how fast you find answers.

💡 Teacher Tip

Let teams organise differently — some will sort by age, others by village, others by occupation. When their Round 2 question targets a different column than they organised by, they'll experience the fundamental database trade-off: you can't optimise for all queries simultaneously.

🎯 Learning Objectives

  • ✓ Experience how data organisation affects retrieval speed
  • ✓ Design a data structure optimised for specific query types
  • ✓ Understand the concept of indexes in databases
  • ✓ Compare sorted vs unsorted data retrieval efficiency

🗂️ Materials Needed

30 census cards per group 5 question cards Answer sheets Stopwatch Coloured markers for sorting Empty boxes/bins for sorting

📌 Step-by-Step Instructions

Distribute Unsorted Data (5 min) — Give each team 30 shuffled census cards face down. Timer is ready.
Round 1 — Unsorted Queries (10 min) — Teams must answer 5 questions: 'How many farmers earn > ₹10,000/month?', 'Who is the oldest person from Rampur?' etc. Race against time. Record answers and time taken.
Reflection (5 min) — 'How did you find the answers? Was it efficient? What slowed you down?'
Design Your Organisation (8 min) — Teams decide how to re-organise their cards before Round 2. They can sort by any column, create sub-groups, make an index card, etc.
Round 2 — Organised Queries (10 min) — Same 5 questions (but new specific values). Compare time with Round 1.
Database Introduction (7 min) — Teacher explains: 'What you designed is a data structure. Databases do the same thing — they create indexes so queries run faster. Google answers your question in milliseconds because data is pre-organised.'
Extension Discussion (5 min) — 'What if you had 30 million census entries? Can humans sort that? What would a computer do differently?'

🧠 CT Pillar Connections

Abstraction
The census cards contain many fields, but answering any single question requires focusing on only one or two — students practise filtering irrelevant data.
Algorithmic Thinking
Designing the search procedure for Round 2 is algorithm design — students create a step-by-step method to answer queries faster than random search.

💬 Discussion Questions

  • Why does the government collect census data every 10 years? How is it used?
  • If you could add one more column to the census card, what would it be and why?
  • How does Swiggy find your order among millions in under a second?
  • What's the difference between organising data and understanding data?