Variables, Data Types, and Expressions
Ages 16–18Difficulty adapts to you
Variables, Data Types, and Expressions
A variable is a named place for a value. Data types describe what operations make sense: integers, real numbers, strings, and booleans behave differently. Parentheses and operator precedence prevent ambiguous expressions.
Your goals
- ✓You can store values safely and combine arithmetic, comparison, and logical operators.
- ✓You can use Variables, Data Types, and Expressions, model correctly.
- ✓You can use the definitions, units, assumptions, and examples to check your answer.
Words to know
- Variables, Data Types, and Expressions:
- Store values safely and combine arithmetic, comparison, and logical operators.
- model:
- A rule or representation used to describe a situation and make a prediction.
Examples
- 1total = price × quantity; is_valid = total ≥ 0.
- 2Converting a text value such as "42" to a number is different from adding the characters "4" and "2".
Check these
- • Do not skip the meaning of a term or give a result without explaining what it means.
- • Keep every number, symbol, label, and unit in its correct place.
- • Show enough working to check how you reached your answer.
Helpful habits
- • Read the whole question before choosing what to do.
- • Show one clear step at a time and check each step.
- • If you are stuck, draw a model, try smaller numbers, or revisit the example.
Now try your own
Create your own variables, data types, and expressions example, solve it, and explain how you checked it.
Professor Wise Owl
Wisdom & Understanding“Understanding "why" is more powerful than memorising "how".”