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🔗 Technology Class: Blockchain

🎯 Warm-up Discussion

Let's explore what you already know about blockchain:

Vocabulary Practice: Key Terms

Before watching the video, review these important blockchain terms:

Blockchain: A technology that stores data in linked blocks securely.
Ledger: A digital record book that stores transactions.
Hash: A unique code that protects and validates data in a block.
Node: A computer that participates in a blockchain network.
Decentralized: A system without a central authority, distributing control among participants.
Immutable: Cannot be changed or altered.
Proof of Stake: A method of validating transactions based on coin ownership.
Smart Contract: A program that automatically enforces agreements on blockchain.

🎥 Listening Exercise

VIDEO: https://www.youtube.com/watch?v=tvw41JcMzd0

Part A: Fill in the Blanks

Listen to the video and complete the sentences with the missing words.

1. Blockchain is an ledger that stores information.
2. In 1991, scientists came up with the idea of creating a database to store documents that cannot be , , or .
3. Every transaction on the blockchain receives a to make it untamperable.
4. A copy of all transactions is stored on all or on the network.
5. A block contains three things: the , the , and the of the previous block.

Part B: Multiple Choice

Choose the correct answer (A, B, or C) according to the video.

1. What is blockchain?
A) A ledger that can be changed easily.
B) An immutable ledger that stores information.
C) A database only for cryptocurrencies.
2. How does blockchain ensure information is untamperable?
A) By using timestamps on transactions.
B) By hiding data from users.
C) By deleting old transactions.
3. Where is a copy of all transactions stored?
A) On one main computer.
B) On all computers (nodes) in the network.
C) On the cloud only.
4. What does a block contain?
A) Only data and the current hash.
B) Data, a hash, and the previous block's hash.
C) Only the hash of the previous block.

Vocabulary Exercise: Match Terms with Definitions

Match each word with its correct definition:

1
Blockchain
2
Ledger
3
Hash

Reading Exercise: Blockchain Developers' Projects

Read about four programmers and their blockchain projects:

1. Alice

"When I first heard about blockchain, I had very little idea of how it worked. Since I wanted to develop an app that helps small businesses track shipments and payments securely, I had to start learning from zero. I studied the basics of blockchain ledgers, how hashes work, and the role of nodes in the network. It was challenging at first, but gradually I understood how blockchain guarantees security and transparency. Now, my app is helping several local companies reduce fraud and improve trust with their clients."

2. Ben

"I have been working in the blockchain field for more than three years now. My current project focuses on solving one of blockchain's biggest problems: scalability. Traditional blockchains can only process a limited number of transactions per second, which slows everything down. To fix this, I am developing a system based on advanced proof-of-stake algorithms that will increase transaction speed dramatically while keeping the network secure and decentralized. It's exciting to be part of this cutting-edge technology."

3. Clara

"My project is a decentralized voting platform designed to make elections more transparent and secure. Before starting, I already had experience with cryptocurrencies and smart contracts, so I didn't need to study the basics of blockchain. Instead, I focused on designing a user-friendly interface and making sure the platform could handle real voting scenarios without errors. We are currently testing it in several local elections, and the feedback has been very positive. This project can potentially reduce election fraud worldwide."

4. Daniel

"I'm working on a project that uses blockchain technology to secure and manage medical records. This is a very complex area because of strict privacy laws and the sensitive nature of health data. That's why I'm building a private blockchain network that only authorized hospitals and medical professionals can access. This way, patients' information is protected, and records cannot be altered or accessed by unauthorized users. The goal is to improve data security and streamline medical information sharing between institutions."

Match each statement to the correct person:

A
Has a long history working in blockchain and focuses on increasing how fast transactions can be processed.
B
Developed an app to improve reliability in business payments without previous knowledge of blockchain.
C
Created a voting platform and had previous knowledge of cryptocurrencies.
D
Works with a sensitive industry requiring data privacy and restricted access.
E
Needed to study blockchain basics like nodes and hashes for their project.
F
Is using proof-of-stake to address blockchain limitations.
G
Their work is currently being tested in real-world voting events.
H
Aims to make medical data sharing more secure between institutions.

💬 Speaking Section: Blockchain

Discussion cards for meaningful conversation

Have you worked with blockchain technology?

💡 Discussion tips:

  • Share your experience: smart contracts, cryptocurrencies, NFTs
  • Use vocabulary: decentralized, distributed ledger, consensus
  • Discuss development challenges you encountered
Blockchain beyond crypto: what are the real use cases?

💡 Discussion tips:

  • Reference video examples: healthcare, supply chain, voting
  • Apply vocabulary: transparency, immutability, traceability
  • Share industries you think could benefit
Is blockchain really more secure than traditional databases?

💡 Discussion tips:

  • Debate decentralization vs centralized security
  • Discuss 51% attacks, smart contract vulnerabilities
  • Use comparative forms: "more secure than...", "less vulnerable to..."
Would you trust blockchain for voting systems?

💡 Discussion tips:

  • Apply vocabulary: transparency, anonymity, verification
  • Discuss pros: tamper-proof, auditable; cons: complexity, accessibility
  • Use modal verbs: "should", "could", "might"
What's the biggest challenge developing on blockchain?

💡 Discussion tips:

  • Discuss scalability issues, transaction fees, energy consumption
  • Talk about smart contract security and auditing
  • Share experiences with Ethereum, Solana, or other platforms
Transparency vs Privacy: can they coexist in blockchain?

💡 Discussion tips:

  • Reference the video concept of transparent yet private transactions
  • Discuss zero-knowledge proofs, private blockchains
  • Debate healthcare records: need privacy but benefit from transparency
Are NFTs the future or just a fad?

💡 Discussion tips:

  • Apply vocabulary: non-fungible token, smart contract, ownership
  • Discuss real utility vs speculation
  • Use future tense: "I think NFTs will...", "They're going to..."
How would you explain blockchain to a non-technical person?

💡 Discussion tips:

  • Practice simplifying complex concepts
  • Use analogies: "It's like a public ledger that..."
  • Avoid jargon, focus on benefits and real-world examples
Will decentralized apps (dApps) replace traditional apps?

💡 Discussion tips:

  • Compare user experience, performance, accessibility
  • Discuss Web3 vision vs practical reality
  • Reference vocabulary: decentralized, peer-to-peer, trustless
What industry needs blockchain most urgently?

💡 Discussion tips:

  • Reference video industries: finance, healthcare, supply chain
  • Apply vocabulary: traceability, verification, fraud prevention
  • Use superlatives: "the most important", "the biggest impact"

🎯 Conversation Starters:

  • "When the video mentioned decentralization, I thought about..."
  • "In my opinion, blockchain's biggest advantage is..."
  • "I'm skeptical about blockchain because..."
  • "If I could build a dApp, it would..."

💡 Remember to use blockchain vocabulary: decentralized, distributed ledger, smart contract, consensus, immutability, transparency!