Grade 08: Computing

In this unit, 'Databases and queries', you learn to create tables and write simple queries. You work with notes, a worked line and a self-mark. You see it, say it, then do it alone.

• See it: watch or try the skill in 'Databases and queries' on a teacher screen or a safe device.
• Name the parts: write the key words and what each part does.
• Use it: create tables and write simple queries. Save your work in a named file or folder.
• Test and fix: run it, find one fault, correct it, and note what you changed.

Step by step.

1. Step 1, Create a table: A learner opens a database tool and types: CREATE TABLE students (id INTEGER PRIMARY KEY, name TEXT, grade INTEGER, score INTEGER); The tool replies that the table was created, with four columns and no rows yet.
2. Step 2, Insert data: He types INSERT INTO students VALUES (1,'Learner 1',8,72),(2,'Learner 2',8,91),(3,'Learner 3',8,65),(4,'Learner 4',8,88); The tool reports 4 rows added. Text values are in quotes, numbers are not.
3. Step 3, Select all: SELECT * FROM students; shows all 4 rows and 4 columns. The star means every column. The learner checks the output matches what he typed, which verifies the insert.
4. Step 4, Filter and order: SELECT name, score FROM students WHERE score >= 80 ORDER BY score DESC; returns two rows: Learner 2 91 first, then Learner 4 88. Learner 1 at 72 and Learner 3 at 65 fail the WHERE test.
5. Step 5, Aggregate: SELECT COUNT(*) FROM students; returns 4. SELECT AVG(score) FROM students; returns 79.0 because 72 plus 91 plus 65 plus 88 is 316, and 316 divided by 4 is 79.
6. Step 6, Update and check: UPDATE students SET score = 70 WHERE id = 3; changes Learner 3 from 65 to 70. Running AVG again gives 80.25, since the total is now 321 and 321 divided by 4 is 80.25.
7. Your turn: Table books(id, title, pages) with (1,'Sea',120),(2,'Sky',200),(3,'Sand',80). List books over 100 pages shortest first, and count them. Model answer: SELECT title, pages FROM books WHERE pages > 100 ORDER BY pages ASC; gives Sea 120, Sky 200; adding WHERE pages > 100 to COUNT(*) gives 2.

Activity. About 30 to 40 minutes of class work, then one short practice task for home. Keep evidence: a worked task and a corrected copy.

Standard to meet. Create tables and write simple queries: at least 8 of 10 marks on a short task, with one line of reasoning for each answer.

In this unit, 'Programming with functions and lists', you learn to break a task into functions and use lists. You work with notes, a worked line and a self-mark. You see it, say it, then do it alone.

• See it: watch or try the skill in 'Programming with functions and lists' on a teacher screen or a safe device.
• Name the parts: write the key words and what each part does.
• Use it: break a task into functions and use lists. Save your work in a named file or folder.
• Test and fix: run it, find one fault, correct it, and note what you changed.

Step by step.

1. Step 1, Break the task into parts. Task: report on five test marks. Parts: find the average, find the highest mark and count how many passed with 50 or more. Each part becomes a function, a named block of code that can be reused and tested on its own.
2. Step 2, Store the data in a list: marks = [56, 72, 45, 88, 67]. Counting starts at 0, so marks[0] is 56 and marks[-1] is 67. marks[1:3] is the slice [72, 45]. len(marks) is 5. A list keeps related values together under one name.
3. Step 3, Write a function with a parameter and a return value. def average(items): return sum(items) / len(items). Calling average(marks) gives 328 / 5 = 65.6. The word return sends the answer back. The max(marks) built-in gives 88.
4. Step 4, Write a function with a loop and a decision. def count_pass(items, limit): count = 0, for x in items: if x >= limit: count += 1, then return count. Calling count_pass(marks, 50) returns 4, because 45 is the only mark below 50.
5. Step 5, Change the list and run the functions again. marks.append(90) adds a sixth mark. Now len(marks) is 6 and average(marks) is 418 / 6 = 69.67. The functions work with the longer list without any rewriting, which is the benefit of breaking a task into functions.
6. Step 6, Your turn: temps = [21, 25, 19, 30, 24]. Write a function that counts the temperatures above 22, and find the average. Answer: count is 3 (25, 30 and 24), and the average is 119 / 5 = 23.8.

Activity. About 30 to 40 minutes of class work, then one short practice task for home. Keep evidence: a worked task and a corrected copy.

Standard to meet. Break a task into functions and use lists: at least 8 of 10 marks on a short task, with one line of reasoning for each answer.

In this unit, 'Web pages with HTML and CSS', you learn to style a multi-page site. You work with notes, a worked line and a self-mark. You see it, say it, then do it alone.

• See it: watch or try the skill in 'Web pages with HTML and CSS' on a teacher screen or a safe device.
• Name the parts: write the key words and what each part does.
• Use it: style a multi-page site. Save your work in a named file or folder.
• Test and fix: run it, find one fault, correct it, and note what you changed.

Step by step.

1. Step 1, Plan the site: A learner builds a 2-page site for a class garden club: index.html (home) and about.html (members), plus one shared style.css. Keeping all three in one folder makes links simple.
2. Step 2, Shared navigation: In both pages she puts <nav><a href="index.html">Home</a> <a href="about.html">About</a></nav> inside the body. Clicking Home or About now moves between the pages from either one.
3. Step 3, Link the stylesheet: In the head of both pages she adds <link rel="stylesheet" href="style.css">. Without this line the CSS file would be ignored, so every page that wants the style needs it.
4. Step 4, Write CSS: In style.css she writes body { font-family: Arial, sans-serif; background-color: #f4f4f4; } and h1 { color: #036; } and nav a { margin-right: 12px; color: #0a6; }. Each rule has a selector and property: value; pairs.
5. Step 5, Check both pages: She refreshes index.html and about.html. Both have a light grey background, dark blue headings, and green links spaced 12 pixels apart. One change in style.css affects both pages, which saves time.
6. Step 6, Fix an error: The About page is not styled because she wrote href="styles.css" with an extra s. She changes it to style.css, refreshes, and the style appears. Matching the exact file name is vital.
7. Your turn: Add a third page contact.html with the same style and nav. Model answer: copy the head including <link rel="stylesheet" href="style.css">, add a Contact link in the nav of all 3 pages, and check each page shows the grey background.

Activity. About 30 to 40 minutes of class work, then one short practice task for home. Keep evidence: a worked task and a corrected copy.

Standard to meet. Style a multi-page site: at least 8 of 10 marks on a short task, with one line of reasoning for each answer.

In this unit, 'Safe use of artificial intelligence tools', you learn to use AI tools responsibly and check their answers. You work with notes, a worked line and a self-mark. You see it, say it, then do it alone.

• See it: watch or try the skill in 'Safe use of artificial intelligence tools' on a teacher screen or a safe device.
• Name the parts: write the key words and what each part does.
• Use it: use AI tools responsibly and check their answers. Save your work in a named file or folder.
• Test and fix: run it, find one fault, correct it, and note what you changed.

Step by step.

1. Step 1, The task: A learner asks an AI tool, 'What is 15 percent of 240?' The tool replies, '15 percent of 240 is 34.' The learner remembers that AI tools can sound confident but still be wrong, so he plans to check.
2. Step 2, Check by calculation: He works it out himself. 10 percent of 240 is 24 and 5 percent is 12, so 15 percent is 24 plus 12, which is 36. The tool was wrong by 2. Only the calculation can prove the correct answer.
3. Step 3, Ask it to show reasoning: The learner writes, 'Show your steps.' The tool now says 240 times 0.15 equals 36. A second try with working gives the right result, but he does not trust it until he has also checked it by hand.
4. Step 4, Check a source claim: The tool says a book called 'The Desert Rain' by a named author proves a fact. The learner searches the school library catalogue and finds no such book. He treats this as an invented source and does not cite it.
5. Step 5, Protect privacy: The learner was about to paste his full name, home address and a class photo into the tool. He stops, because anything typed may be stored. He removes the personal details and asks only about the maths.
6. Step 6, Use honestly: His homework is to write about deserts. He uses the AI for ideas, writes the answer in his own words, checks two facts in a trusted encyclopedia, and tells his teacher he used AI for ideas.
7. Your turn: An AI says the capital of a country is a city you doubt. What do you do? Model answer: check a trusted atlas or government site, trust the match with two reliable sources, and note that the AI was unreliable.

Activity. About 30 to 40 minutes of class work, then one short practice task for home. Keep evidence: a worked task and a corrected copy.

Standard to meet. Use AI tools responsibly and check their answers: at least 8 of 10 marks on a short task, with one line of reasoning for each answer.

On the slide: L1 Basic · What a computer does

Notes: Name the four jobs of a computer: input, process, output and storage. Notes: use a washing machine or a phone and label each job with a sticky note; no screens are needed. Learners say which part is the input and which is the output.

On the slide: L2 Awareness · Steps and algorithms

Notes: Describe an algorithm as ordered steps and put a set of steps in the right order. Notes: cut up the steps for making a sandwich and mix them; learners order them and find what breaks if two swap. Work unplugged. Safe knife use is for an adult only.

On the slide: L3 Foundation · Code loops and variables

Notes: Write a short program that uses a variable and a loop to give a predicted output. Notes: for i in range(1,6), print the square of i. The output is 1, 4, 9, 16, 25 and their total is 55. Learners predict the output first, then run and compare. Take breaks to rest eyes.

This course: Grade 08 Computing is at this level. Its units include Databases and queries; Programming with functions and lists; Web pages with HTML and CSS; Safe use of artificial intelligence tools.

On the slide: L4 Practitioner · Binary and image size

Notes: Apply binary and storage sums to convert numbers and estimate file size. Notes: 45 in binary is 101101, since 32 plus 8 plus 4 plus 1 is 45. A raw picture of 800 by 600 pixels at 24 bits needs 1,440,000 bytes. Learners check by working back from binary to decimal.

On the slide: L5 Specialist · Network transfer and security

Notes: Analyse how data moves over a network and compare protections against common threats. Notes: a 50 MB file is 400 megabits; at 20 megabits per second the transfer takes 20 s. Learners work out the time on a slower link and list two safe habits for passwords and updates.

On the slide: L6 Advanced · Complexity and search

Notes: Apply Big O reasoning to compare linear and binary search. Notes: a sorted list of 1,000,000 items needs at most 20 comparisons by binary search, since 2 to the 20 is 1,048,576, instead of up to a million for linear search. Learners trace a search on 16 numbers by hand.

On the slide: L7 Super expert · Secure system design

Notes: Evaluate a small system for security risk and design controls. Notes: a 12-character password from 62 symbols holds about 71.5 bits of entropy, since 12 times log2 of 62 is 71.45. Learners rank threats, choose controls, and test only on systems they own or have written permission to test.