Programming Basics

1. What is a program?

A program is a set of instructions that tells a computer what to do. Computers are fast but not clever. They only do exactly what we tell them.

Think about making a cup of tea. You know to boil the kettle before pouring water into the cup. A computer needs that same order of steps written down.

2. Algorithms

An algorithm is a step-by-step plan for solving a problem. It doesn’t have to be in code. A recipe is an algorithm!

Algorithm for making toast:

1. Take a slice of bread.
2. Put it in the toaster.
3. Push the lever down.
4. Wait until it pops up.
5. Add butter.

3. Variables

A variable is a named box that stores a piece of information so we can use it later. Picture a labelled drawer.

# Variables in Python
name = "Ava"
age = 13
score = 0

The name on the left is the label; the value on the right is what’s in the drawer. You can change what’s in the drawer at any time.

4. Decisions (if / else)

Programs make decisions using if statements. The computer checks a condition, then chooses what to do.

if score >= 10:
    print("Well done!")
else:
    print("Keep trying.")

Read it in English: “If the score is at least 10, say ‘Well done!’. Otherwise, say ‘Keep trying.’”

5. Loops

A loop repeats a block of code. Instead of writing the same thing 10 times, we tell the computer to repeat.

for i in range(5):
    print("Hello!")

This prints “Hello!” five times. Loops are what make games, animations and data processing possible.

6. Bugs & debugging

A bug is a mistake in your code. Debugging is the skill of finding and fixing bugs. Every programmer (even experts) writes bugs. That’s normal.

• Read the error message carefully; it usually points to the line.
• Check your spelling and capital letters.
• Try the smallest possible version of your code to isolate the problem.
• Explain the code out loud to a classmate (or a rubber duck!).

Glossary

Algorithm

A step-by-step plan to solve a problem.

Variable

A named store for data.

Condition

An expression that is either true or false.

Loop

A block of code that repeats.

Bug

A mistake in a program.

Syntax

The grammar rules of a programming language.